Dunno what is applicable to Kappas...but changing the trans fluid on my Camaro did nothing for shifter "feel".
Changing the clutch DID make a difference. So did the Hurst short-throw shifter kit.
I'd start by checking the linkage and making sure everything is happy. (Not worn, properly lubricated, etc.) Then, I'd make sure the clutch is disengaging properly. (the issue on my Camaro. It wasn't. (isn't))
I did change the fluid of my TR6060 to RP Syncromesh, but that had to do with expected temps/wear/abuse from racing, not seeking a better shift "feel". That being said, I changed my clutch last spring and the trans fluid was still purple...after two years of use and abuse. Bottom line, unless the manual says change and/or you see trans temps over 180*F I don't think anyone needs to worry about trans fluid in a manual...unless you grenade it, but then you've got bigger issues...