I’m not sure how you managed to get it working since a few lines below there is a static assert checking that MAX_SRVS is not bigger than what the srvSlotMask can hold. Which since it is stored in a uint64 cannot handle more than 64 SRVS.
Would love to get an opinion from epic though, since 64 SRVs is very easy to reach when using multilayer materials, and it limits a lot its potential.