So just for reference (looking at screenshots, don't really wanna put it back to defaults to check) at idle ---
Default it was drawing 76w @1.376v with package temp of 52.6c, ccd#0 38.8c & ccd#1 40.5c
VID lowered to 1v is now 35w @ 0.9v with package temp 46c, ccd#0 35.3c and ccd#1 33.3c
Stock 26% util (installing a program for like 10 seconds) saw 73c package temp, whereas now running p95 also for 10 sec with 100% util package temp is 50c so a massive temperature difference. Cinebench I compared vs one online, and mine scored 2000 and stock scores should be 2400, so obviously performance is taking a hit now being clocked so much lower but until I hear back from Asrock on whether it's normal behaviour or not I feel much more comfortable leaving it with a voltage cap. Has been 100% stable and isn't even close to being a bottleneck so all good for the moment.
Also, in case it makes a difference whatever the max vid is set at, it just sits there.. so me setting it to 1v it varies from 0.9-1v, but stock setting was 1.425v and never went lower than 1.36.. surely it has idle states where it should drop down much more? Again, not too clued up on AM5 but pretty sure it should.