I propose a minor change into election algorithm. Everybody who wears a paid signature should be considered unworthy for DT1.
The motivation is simple, paid signatures are reason to question their judgement.
You can start by not including such users in your own trust list.
DT1 is actually no different from the MPs, judges or court officers in that term.
DT1 is not a paid position. It's more like a town council or a school board - not a full-time position and members typically have day jobs. If you have specific examples of how signature campaigns corrupt DT members you should probably bring it up.
Meant this to be a 5 merit transaction but enjoy the 25 fatfinger.