Curseforge has a "2.7.85" version, dated May 18th. It says that it includes patches from PG85.
But: The github does not show any merge from PG's code back to the main MCTCP code.
Which version is the "v4" that you used in biome bundle?
... Maybe it's time to decompile V7, get the biome packet handling code, patch that into the MCTCP code / PG's github changes (or decompile V4 and patch the V7 fix into that?)