While your point is taken, the OP doesn't specify that the POD is Poland's revolution, merely that it occurs as one butterfly among many.
So for instance, if the January 1934 German-Polish Non-Aggression Pact negotiations had ended without success and indeed a public spat where Beck accuses Pilsudski of selling out Poland and France to Hitler,
Beck got his position by Pilsudzki's favor only and had no power base on his own. Not mentioning that when it came to Pilsudzki he was pretty much a yes-man. Beck would have to be completly drunk and have a concussion to even contemplate disagreeing with Pilsudzki. And that would only get him kicked out of corridors of power. So not happening.
and if Litvinov convinces Stalin later in the year that Beck might be a useful tool then the Polish communists may be instructed to soften their stance to some elements of the government.
Upon Pilsudski's death in May 1935, the KPP starts getting together with Beck to look at options to ease out Rydz-Smigly and Mosicki, and the Moscow-based contingent start to trickle back to Warsaw. When the Anglo-German Naval Treaty is announced, that triggers Stalin's paranoia and he gives the go order for a coup. Beck is of course tragically shot by "revisionist Pilsudskiite reactionaries" part way through the affair, but things settle down into an uneasy mob-rule (Hitler is not able to intervene, having little army and intending to use it next year in the Rhineland).
If KPP tries a coup, it ends with it being utterly crushed. They had almost none (less than 1%) supporters in officer corps.
Not mentioning that within Sanacja there were no communist-lovers at all.
tl;dr: above scenario is ASB
Now to not be completely negative, there may... may be a way to get communist Poland. But it'd take more time and multiple PODs:
1. There must be more radicalisation of opposition to Sanacja. Maybe Dąb-Biernacki gets too eager and some opposition MPs die in Brest-Litovsk in 1930, making them martyrs. Which along with Great Crisis would cause mass demonstrations. Get officers on the field to overreact, and you get radicalisation spiral.
2. OTL in 1936-7 there were talks between PPS (socialists) and KPP about some kind of alliance - on KPP's insistence, in the vein of Popular Front. It was doubtful it would came to anything, but any chances were scuppered when on Stalin orders KPP got purged - so ITTL purge of KPP must not happen.
3. Let's say that afterwards a Popular Front (or Centrolew) comprising of SL (agrarians), PPS and KPP wins the elections. Say soon afterwards some officers (with Presidents support) try to coup, but they don't manage to overtrow the parliament, yet manage to throw Poland into civil war.
4. Civil war fosters increasing radicalisation, and with indirect USSR support KPP takes over the goverment.
In short Spanish Civil War in Poland. All KPP has to do is to win it.