Hi! I know there was already a similar post regarding equipment incompatibility for Power Armor MK3, but I found the cause so I figured it was worth posting another topic.
When Krastorio 2 is enabled alongside Rampant Arsenal, it heavily limits what equipment can be inserted into the Power Armor MK3 from this mod. After checking the files, I'm guessing it's due to the way Krastorio 2 changes equipment categories, but I unfortunately don't have enough modding experience for it to be anymore than a guess. What I do know is that equipment like the personal roboport (as well as other equipment like big personal batteries and the personal generator, though these are also from Krastorio 2 and not vanilla) can be equipped when Krastorio 2 is disabled, but becomes unequippable when Krastorio 2 is enabled.
I'm not sure if this is something that can be fixed on Rampant Arsenal's side or if it requires a fix from Krastorio 2, but I wanted to make a post about it in case a fix can be made. Thanks for taking the time to read and thank you for the mod!