Modular rig is a powerful tool and was daunting at first but hopefully this will help you skip all the hurdles and wall I hit learning to use it.
Modular rig made it possible for me (non-rigger) to make a control rig for a manatee character in Unreal without having to make a complicated control rig from scratch
https://dev.epicgames.com/community/learning/tutorials/O4b8/unreal-engine-rig-your-characters-with-modular-rig-in-ue5-without-rigging-experience-step-by-step-tutorial