Client-bundled PPv2 shaders are now forced even on worlds uploaded with 2018 unity.
User-modifed shaders used to work fine at least up until udon open alpha - actual regression point unknown.
Tested with
.12 and
.14 unity versions, both older SDK and newest as of writing: VRCSDK2-2019.12.21.16.01
Repro world with Uber shader modified to do desaturation - everything should be in grayscale: wrld_83d10c78-8449-4a22-95e0-284daf50adcf