Some owners in leagues where rules are defined either plead ignorance or wilfully abuse things. Not going to name names, seen quite a few things over my time.

Underweight players played in different positions etc. I'm not going to name specific tricks, they are well enough known.

League admins simply don't have the time to monitor every roster, every game in leagues where it's agreed those things should not happen.

Is it feasible for tools to be provided whereby league admins can select / define rules and receive private message notification for example?

If it's agreed, for example, only players of an assigned position can put into the depth chart / on overrides, where their weight is say within 5 lbs of the weight for the limit, then as part of the sim process apply those checks. Run midweek too, league admin can then notify offenders.

Add in "punishments" - removal of picks?

I've seen owners follow custom rules during the regular season only to use the punt block exploit in the playoffs. Then they play stupid after getting called out.

I run USFL and we used to have custom rules but I grew tired of creating and enforcing rules to fix a broken game so now we have no custom rules.

It should not be up to league administrators to create custom rules to fix the game, but if it remains that way, at least give us some options like Martin asked.

Are you implying some players are tools, or asking to have tools to control them?

Yes

*snortles*
:)