I suppose you have good reason to believe that anyone choosing to read a late-Roman TL would already know what a "Pronoia" is. This is not my area of enthusiasm generally but I do think I've picked up some fair knowledge of the Eastern Roman system over the decades, and I had not heard of the term or forgot it if I had.
For general information of others as ignorant as I was until looking it up today,
I suppose the Wikipedia page is reasonably useful.
My takeaway is that the person holding this grant, the
pronoeir, is basically granted the right to tax-farm the grant; the term "
pronoia", meaning "forethought " literally, can mean the territory (or apparently other revenue sources could be granted), the value estimated of the grant, or the actual revenue stream produced. In Latin the corresponding term for each pronoearios would be "
curator." The class of persons (I don't know if any were ever women, but institutions such as monasteries could hold the office) is
pronoetes; the persons included in the grant to tax are "
paroikoi." (Am I right in thinking that word relates to the English word "parishoners" in etymology? As in "parochial"?)
This is not the same as west European feudalism in many respects. The Pronoeir may tax their paroikoi and keep part of the revenue, forwarding the rest on to the Imperial treasury, but they have no authority to say draft any paroikoi to military service, nor does the granting of a Pronoia to a Pronoeir create any feudal obligation for the latter to provide military service in person or sending any specified troops. At least until the final generations of the empire OTL, the office is not hereditary (though if granted to an institution, obviously it would be perpetuated until either than body was extinguished or the Emperor revoked it). Indeed the grant is revocable.
Per the article:
From that I infer that each Pronoia grant was pretty much ad hoc, though I would guess in a particular time frame a grant to a particular category of candidate was closely equivalent to such a grant to another recipient in a similar status. But the precise terms in each praktika might be wildly at odds with those in another, granted to a person of higher or lower status or in a different time frame when the negotiating position of the Emperor was different, stronger or weaker.
The key point I think is that the Emperor could revoke them, so in terms of useful aid to the Empire, an Emperor was in a position to make sure they contributed a reasonable amount. I don't know if the praktika generally put upper limits on the power of the Pronoiar to extort from their parikoi, but if not obviously two practical limits would exist--one, extreme rapacity would drive the parikoi into revolt in sheer desperation, also somewhat less extreme extortions could visibly break the ability of the parikoi to yield sustainably, so prudence would tend to set an upper limit, versus the desperation or relaxation of a particular situation. Two, the Emperor overseeing it all could get wind of extremism in this matter--aside from the astute desire to maintain loyalty and morale among subjects, and a reputation for justice for Imperial institutions, an Emperor might well suspect the purpose of squeezing the parakoi is to build up a war chest in a bid for the purple or perhaps secession as a splinter state.
At the other end of the scale, I presume the Treasury expected a certain revenue, probably often or maybe always stipulated in the praktika granting this Pronoia, and failure to forward that amount in full would bring down suspicious and angry inquiries and investigation pronto. Perhaps such inquisitions would be satisfied to see specific hardships such as plagues or famines plainly smiting the region and forbear in such hard years, but the Pronoiar would be best advised to send in the expected revenue at whatever cost, to maintain the good will of the Emperor and his court and avoid hostile scrutiny.
The bit about the lack of any
inherent military obligation of the Pronoies to serve themselves or provide specific levies
inherently suggests the Empire maintained direct fidelity of sworn officers and troops to the Emperor himself.
OTOH, I would expect that Emperors often did tell Pronoiar that they were in fact drafted, probably on an officer level of course, and bloody well would provided some levies of a thousand or so as auxiliaries. The Pronoiar is not bound to obey but then, the Emperor grants and rescinds at personal pleasure, so the option is practically to either comply or rebel. Presumably any troops raised this way are folded into the regular ranks, with something of a watchful eye on inexperienced or questionably loyal Pronoies and factoring the greenness or indiscipline of suddenly drafted levy troops--either in practice deploying them as auxiliaries, or with them folded into regular bodies, generals and sergeants are on the lookout for substandard behavior.
Also, this smacks of actual feudalism to me:
Around this same time, it is my impression the Crusader Kingdom of Jerusalem reversed this--the King, Baldwin or his heirs, controlled all tax collection, and granted his knights fixed salaries he doled out to them from the collective revenues. (I don't know if the knights just had specific salaries granted them generically, or if on paper each one was collecting from specified tracts of territory the kingdom was parceled out into, but either way, I believe they had no direct control of the process of taking and keeping the revenue. However unlike Pronoies, these knights did pass their claims and obligations on to their heirs in a hereditary fashion).
As a practical matter, the KoJ's knights resided in big cities, not dispersed over the countryside as in the Pronoia system.
Per the article, on the whole it was a good thing for the Empire the Pronoies were dispersed to their rustic or distant bailiwicks: on the downside, they could and sometimes did plot disloyalty and organize locally for various kinds of subversion, but the fact their power centers were far from the capital was more benefit than the decentralized potential for rebellion was cost.
As with feudalism, dispersing and devolving much bureaucratic burden to self-interested Pronoies would also mean the wealth of the Empire in a logistic sense was dispersed as well, meaning Imperial forces thrown upon some threatened zone could be supported with resources largely at hand, including raising local auxiliaries; in peacful periods regular imperial forces could be dispersed to provide stiff resistance against surprise attacks, then others pour in from the region and eventually whole Empire.
So I infer anyway.
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