In reply to BruceM:
Thanks for input so far.
Yes, I should add that I'm talking about the likes of Sportiva Trangos, Nepal Extremes (all their variants), and all the Scarpa equivs. So we are talking Mountaineering/Climbing types of boots.
Do agree that Scarpa Rebels are slightly lower heel rise,, esp the Orig Rebel Lites. But unfortunately I can't wear Scarpa because of other foot/heel probs and their big heel-lock internal padding that all their boots have.
I've been using Mammut Monoliths and Mamooks until recently (when I've burnt them out), because these boots have a big solid plastic support thingy ("Motion Control") on the medial side of the ankle which is brilliant! Compared to say a Trango, the Monoliths are soooo supportive. Unfortunately they have stopped making these.
So yes I'm using low-rise approach shoes for walk-ins, low-rise orig 5.10 Tennies, for scrambling...but now it is winter again...
I should also add that my feet are quite massive but low volume for my frame. Size UK 10.5-11 feet on 172cm 62kg. So there is a massive torque from these big flippers aggravated by the high heel of the boot, and compounded more by the potentially poor boot fit around the ankle area due to the low volume issue. Proprioreception is definitely an issue. I have done exercises in the past. But I must say any improvement has been relatively insignificant given all the other parameters.
I suspect many people don't have a problem because many people way bigger than me have like size 7 or 8 boots. Must be awesome! Big feet are not so great unless everything else is in proportion!
But I can't help thinking these boot designs are all wrong. Why the high heel? We don't need to run in boots.
The slice out of the heel block idea is still very tempting. Loose 2-5mm...