The mod is currently buggy as the coders are busy with other projects. This is a known problem with a couple simple fixes. The simple approach is to disable the level up requirements using the Constants mod to enable "disable_levelup_gate".
Otherwise these edits should address the issue:
in outside.gd, lines 1584 and 1590, replace levelupreqs with xp_boost_reqs
in statstab.gd, line 1628 has same problem.
replacing those 6 instances in the mod files should resolve the problems. the mod needs to be re-applied to take effect