Not an issue I’ve found between normal / Cupra and I use all 375 horses on a regular basis. Tyres maybe influence it a lot? The biggest difference I’ve found with the diff in Cupra mode is that it tucks / tightens into a corner a lot more aggressively. That is obviously bad if you don’t expect the diff to behave that way but it is obviously a lot quicker around corners as it somewhat negates the tendency to run wide. As a side note, although everything else is in Cupra, I always have the suspension in comfort on bumpy / rutted roads, in fact, most of the time!