When we first setup the server with Better MC 3 (for 1.19.2) and installed the same for our client side, we were able to update the Backpacked config file to change it from 1 row of inventory space to ...
According to #116, MrCrayfish's Backpacked mod is already supported by the texture pack as of version 2023.7.0. However, it seems that Backpacked files are missing in the latest version of the texture ...