No.
You should - SHOULD - feel free to continue trying to perfect the roll because you got lucky initially and have 5, 8 or 10 Temper rolls remaining.
Like rhe Occultist with Enchanting -
KEEP CURRENT ROLL
Screw “oh gosh thanks masters and overlords for adding some convoluted and contrived system to allow me to perfect my item with your not even pseudo-crafting system omg I’m so grateful!”
Hell with that.
Keep the Tempering system unchanged.
Add what’s missing and that’s Player Agency to try to perfect an item with their excess remaining Tempers.
It’s presently a brain dead hollow soulless blind gambling.
Adding Enchanting aka Keep Current Roll/Affix is QoL, 101 design and fulfillment of an empty promis of a customization system.