I found this theme potentially interesting, but not as informtive as I might have wished.
as a constant, but somewhat dissatisfied user of manual lenses on the olympus penF I have been considering the Z as a better alternative and I have examined the risk of inadvertently pressing buttons on the Z that might interfere with manual focussing and light metering.
The penF has a wheel at the back that cannot be disabled (Short of using superglue and losing all opportunities to reach menu settings).
The problem is that when takoing a strong grip to steady a long and heavy lens like the 400mm ED-IF (with a speed-booster= effective 280mm, so still hand-holdable with sensor stabilization), the control wheel is pressed and moves the focus point. When both the spotmetering + enlarged focus point where the focus ahs been set is moved, reframing is bound to fail.
On inspecting the bodies in the local photo shop, I found that the Z has a similar suspicious-looking wheel ready to be squashed, as did the panasonic. the only body free of potentially disastrous buttons was the Leitz- Panasonic clone SL2, but that costs twice as much as the Z.
p.