The upkeep should be lower as the Pronoiarioi basically support themselves. I would decrease it just a bit and increase training costs further if necessary to balance it off.
But that was at the cost of taxes going straight to them instead to the state, so it´s not too unfitting. Besides, it helps to limit the number of PKT in the field, which would otherwise lead to one-unit-type-armies (they´re THAT good. I fielded three units of them against three byzinf and one psiloi unit, and massacred the defenders to the last man, suffering only thirteen losses or so-althrough, truth to be said, using the increased maneuver of cavalry against such a small garrison would have been easy with any kind of heavy cavalry, but instead of charging straightfoward-like I´d have done with chivs- I peppered them beforehand.)
Another alternative would be lowering the support cost and raising both the training cost and training time (justifying it in-game, the time&money investment symbolizing convincing 40 members of the gentry to join your armed forces)

I'm amazed that anyone is still playing the Pocket Mod to be honest. Most seem to have moved on/back to XL or vanilla
Good to see someone still playing the mod though (you're probably the only one).
Well, the mod fits rather well my concept of an "ideal" mod (as in altering the existing gameplay to make it more interesting as opposed to altering everything -XL is one mod I tried and didn´t like (and unfortunately deleted before I could think up looking into things I´d have liked to copy), and vanilla alone is rather tepid after trying your mod. Not that I have much time, as I have to keep up pharma, epidemiology, and general pathology, but when I do a TW, it´s with the Pocket Mod.

Sidenote: I don´t know what did you do with the "compound bow" projectile exactly, but Trebizond-trained Psiloi are MURDERERS. Not only they´re extremely effective in combined arms, but as single units they´re particularily
lethal as well. I moved one to çuell one of the infamous "siege weapons uprisings", and it managed to pull a shot as the rebels were running away, and still managed to kill 4 of the twelve crew. (It does lead to "historically accurate" armies composed mainly of bowmen, and it makes them be worth the extra support, but renders arbalesters a bit accessory, just for bridge battles and/or fencing off the first waves of the mongol invasion -which in my current game has opted to ignore me altogether-.

Maybe it´s just that the Hungarians are weaklings, in truth. In most of the former games I avoided them because Serbia and Bulgaria made a nice border, and this time they took them before I could, so I decided to bring my wrath upon them instead of the turks or the Sicilians-High Age beggining, took Trebizond, then Constantinople, then Greece, then leaped north)