McNaught used to have one of the nicest heels you've ever seen, but he moved to a bulkier heel citing both sound and stability issues. That's enough to convince me, frankly -- you know he can do the nicer heel, it's what he originally envisioned and did for years, so you know it's not a cop out when he goes through the hassle of reconfiguring it for a bigger one.
On Kiesel's CT model (their PRS-alike), the neck heel has some bulk to it. But, you can get a shaved-down heel. I've asked if this was still available a while back, and they said "yes", but it's done by hand, so it's not a cheap or returnable option. When I asked if there were any plans to make it the new standard for the model, the answer was "no".
I didn't get an answer as to why (don't remember if I ever asked) but it could be anything from:
1) "the type of customer that is buying this type of model has certain expectations, and a voluminous/massive heel is one of those"
...to...
2)"It's not a super huge seller anymore, and we just don't want to spend the time/money on re-doing the CNC programs for new necks."
...or...
3) "there is/are some negative consequences to doing this (tonal, the longevity of the instrument, etc) so while we'll do it, we don't want to do it to every guitar."
Standard:
Shaved down:
In comparison, they have two more modern "set-through" guitars, and both have heels that are more svelte:
Crescent:
Chris Letchford signature (which is basically as smooth as their neck-through):