To be strictly accurate, it’s that the implementations on here must be approved by the publisher. This is often cited as “no house rules” because publishers pretty much don’t do that sort of thing. However, sometimes publishers do agree (or even insist) on differences between the physical game and what is here. For whatever reason, Formula D has a list of such variations as long as your arm and you can see them all on the “rules” page on the BGA wiki:
https://en.doc.boardgamearena.com/Gameh ... Variations
Perhaps a dev can speak up as to why these variations are in place but it’s possible not even they know
why, just that they were told to do it.
(Worth noting the rulebook says it was published by Play Machines, but these days it’s an Asmodee property, so maybe somebody Asmodee thought these changes made the game better? But I have no ideal)
