Hey, thanks for the suggestions.
I fixed missing modular-armor incompatibilities in 1.2.0, so Useful Equipment should now work fine. However, because with Spidertron Engineer equipment modules are not placed in the player's armor, the crafting speed increase will probably have no effect. You could use https://mods.factorio.com/mod/Crafting_Speed_Research or https://mods.factorio.com/mod/qol_research to improve mining speed and crafting speed with researches.
I'll certainly consider making the spidertron a bit smaller (particularly the early game ones). There are other mods that modify the spidertron so I can hopefully borrow some of their techniques.
And as of 1.2.1, all gun and armor items that are not needed to create other items have had their recipes hidden, but are not now completely deleted like they were before. Mods that add equipment should work fine (unless the equipment won't work in a spidertron like the crafting speed one, presumably).