I have started playing with tyres and inserts.
I use a full rear insert in the front to act as a hard insert, I am also playing with smaller holes or no holes in the front wheels. In the rear I use an un trimmed insert, a 3 to 4 mill-ish hole in the wheel, I like rear end grip
Then glue all around the edge, an acetone bath gets the tyres off and the inserts are ok with this, then I give my second hand tyres to younger drivers that will use them, speaking of this, I have a huge bag of used tyres and inserts I will be giving out at the next EPR winter series.