When I hack games I’ve got such a hangup to approximately match up with the same end results as the rule I’m hacking, just with a different interface. Like how I immediately wanted to hack the underclock to add up to 20 (just like a doomsday clock gets closer to midnight) rather than subtract. Same way I count monster HP up from zero to their death threshold. That doesn’t change any outcomes, just how we do it.
That hangup is sometimes to the detriment of the game because sometimes the original mechanics that I’m trying to match were just pulled out of a hat. Like, with Ghosts of Saltmarsh I combined the navigation check, hazard check, and encounter check into one die roll with roughly the same probabilities as the original book. That was a great hack in how much the fun-to-bookkeeping ratio increased for our sea voyages in our boatmode campaign, but it failed to take into account that a 1-in-20 chance of a hazard was way too low! Yes, some of the hazards are super intense with a burning ship in a storm but some of the other stuff on that table is weaksauce like “there’s a mild disagreement onboard”. Especially since it replaces a weather table. I was eager to change the rule but since I didn’t wanna tamper with the outcomes, I missed a chance to actually improve them, I just improved the interface to them.
An even worse example is the Golden Voyages weather state machine. I spend so much more work on that; the original rule had an awful interface; a chart buried in one booklet set up as a patch on a chart buried in the 2e DMG. I combined the two charts into one state machine but what I ended up with was a disaster because it exactly matched the same outcomes as those original rules and what I didn’t know was that those original rules were awful—the weather kept quickly ratcheting towards never-ending hurricanes!