Thanks for the detailed reply much appreciated.
Oh one other quick note, it's not on you but I did run into an unlock display issue when installing the monobikes on same server as ocb's lawn tractor. The lawn tractor adds in an unlock display entry before the minibike one so this then throws off your entry to be in the minibike unlock display. Which then causes it to display in game as unlocking at level 20 however passive effect still ends up in the right spot so it still doesn't unlock till 45 though.
I fixed this by changing the append to the unlock display to go by icon instead of third unlock display down. Like so.
<append xpath="/progression/crafting_skills/crafting_skill[@name='craftingVehicles']/display_entry[@icon='vehicleMotorcyclePlaceable']/unlock_entry/@item">,vehicleMonoChassis,vehicleMonoHandlebars,vehicleMonoWheel</append>
I also switched the second line as well just in case but it wasn't needed.
<append xpath="/progression/crafting_skills/crafting_skill[@name='craftingVehicles']/effect_group/passive_effect[contains(@tags, 'vehicleMotorcycleChassis')]/@tags">,vehicleMonoChassis,vehicleMonoHandlebars,vehicleMonoWheel</append>
Anywho I know none of this is on you as it had to do with working with another mod but thought I'd add this note in case you might wanna change it for compatibility.
And big thanks for these mods btw, a friend of mine has just been loving having them on her server.