The rhs javelin does not work with the ace realism mod. It uses the standard locking as it was without ace but the titan compact from A3 vanilla works with the mod? They talk about how the javelin works with ace but it does nothing

Wrong mod but to answer your question:

https://github.com/acemod/ACE3/issues/1321

I believe you need to move the ace_compat_rhs_*.pbo files from you @ace/optionals to @ace/addons to get the full functionality.