A little idea :
Having a "max lvl" different for each job group. By default, it be the same that the default value. For example :
- I have my default townies, they could reach the -8 lvl.
- My townies working at the surface in the "job group 1" will have a 0 lvl
- If i want one townie alone go searching ressource in dangerous lvl, i'll place it in "job group 2" and define this group only for "-10 lvl"
This way, you could prevent your townie to go haul ressource at -6 level when you want them to just bring back the harvested food, without having all your other tasks blocked.