I've tested instances for 1.16.5 with Forge versions 36.0.45 and 36.0.46 using engineersdecor-1.16.4-1.1.8. Neither of the ladders (treated wood and metal) in engineer's decor are now climbable.

Hi zed, thanks for the hint! I included the fix in the today's push (was just a minute adding a few lines of code - a feature was dropped in forge ~.45, but there is another more convenient "ladder convention" in forge that can be used instead). Gonna close directly, cheers!