What i found worked against higher leveled vamps was using a vampire in the bloodline that has the sleep ability and then capture the vampire who will likely remain docile until you get back to your colony, and then medically put them under so you can soul absorb. If you don't have the vampire of that bloodline then other alternatives such as physic items should do fine. Sorry if this is too late for you.

thx but due to FPS problems (as i like 30+ colonists minimum at all times and go up to 50-60)

i stopped using this mod.

i now use this:

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=775650249

How to recruit a vampire when you have it in prison it seems there is no way to reduce resistance.