I’ve tried to change them too without result (values return to default after restart).
Anyway, there’s already a mod in the steam workshop that changes the dodge roll 's speed :
"Dodge Rebalance-Roll Tweak
- Light Armor dodge roll speed increased from 1.6 to 2;
- Medium Armor dodge roll speed increased from 1.23 to 1.5;
- Heavy Armor dodge roll speed decreased from 1 to 0.85.
modded assets:
AM_combat_dodge_roll_base.uasset
AB_human_male.uasset "
I assume nothing is fixed in stone … Wait and see.

