MachineClaw
sorry I have libraries that either require full Kontact 4+ or work with Kontact 5 Player or 5 full.
generally if a library requires the full version of 4 or 5 then they have scripting that requires the full versions. and I don't think they have to pay NI for Player compatability.
MY OrangeTree Samples Strawberry requires full Kontact 4 version cause of scripting and I have full 5 so it works.
(I did not have Kontact 4 full or Player). So like I said if a library requires Kontact 5 Full and does not work with player then of course it would be worth upgrading.
As the fellows from Hollow Sun often point out, the licensing needed to make something Player compatible would prevent them from offering their libraries anywhere near as reasonably priced as they are.