I've wanted to do this in TDL, but not smart enough to come up with a good formula to reduce endurance proportionately. If any rom wiz's out there have a good idea to do this or the Finns formula, I'd love to hear it!
TDL operates with using full-line ups, manual line changes, but no off-sides. I'm not completely against using off-sides as it totally changes the flow of play and strategies coaches have to use to be successful.
If you are looking to get into a line changes league TDL Season 3 will be rolled out in about 6-8 weeks, keep an eye out for the league roll-call as we will be filling open spots and the waitlist with a lottery for S3.
Main reason I think off-sides has been avoided in most leagues is that it more than doubles the average play stoppages per game, not a lot of coaches liked the over abundance of whistles.