1730-1760: Some thoughts on Travancore
OK- some more detail about the errors I mentioned earlier.
Without Hyder Ali, there's unlikely to be a Mysorean invasion of Calicut. This may well mean that Travancore, having defeated the Dutch in the 1740s may then set its sights on Calicut.
The situation as per OTL
Travancore already had an expansionist policy and it seems that its Varma kings had a general plan of uniting the Malayalees under their rule- in previous decades Travancore had already invaded and annexed Kollam and Kayamkullam. This was what triggered the war with the Dutch in the late 1730s and early 1740s. The Dutch were defeated and the peace terms recognised Travancori dominance over Cochin, stipulated that the Dutch would provide Travancore with European arms and officers to train the Travancori army to European standards. It's a very interesting corner of history and one which is overlooked- I don't think there are any other instances of an Indian power fighting an European one to a standstill. ITTL the Travancori army trained to Dutch standards was able to hold the line against Tippoo Sultan's forces from Mysore until the EIC joined the fight.
In TTL
Without a Mysorean invasion of Calicut, it's quite likely that Travancore would seek to continue its expansion Northward. Calicut would be the only Malayalee state to remain outside the dominion of the House of Varma and would be the obvious next target for invasion and annexation in the 1750s.
This has two interesting repercussions.
1) The Travancori policy is interesting in that it seems to have been a conscious drive to unite the Malayalee ethnic group under one crown. This will certainly have implications for 19th C nationbuilding. The Malayalee nation will already have a story of unification to use as building blocks for a national identity.
2) It puts Travancore in an interesting position as the only Indian state to have fought an European power to a standstill. This might mean slightly more manouvering room for Travancore as the English and French may well take the state a bit more seriously as it will now have a proven record of being able to punch above its weight. Both or either might be quite happy to court it as a local ally.
As much as I hate to deface this beautiful map I found, this is a summary of the situation as it was after the Dutch-Travancore War. Everything South of the black line is Travancore territory. Cochin retains its own Maharaja but as a powerless Travancori vassal. The Dutch have a trading post in Cochin itself but do not garrison the city. The spice trade is firmly in Travancori hands.
Now, by 1760, Travancore will probably strike North to impose a similar vassalage on Calicut. Calicut itself will retain its Zamorin but most of it's territory will be annexed by Travancore (as was the case with Cochin).