Surely it should be possible to design brake callipers or adapters to have some kind of micro-adjustment screw/mech in them to avoid the faffage of undoing the mount bolts and trying to adjust the position? Something with a screw/bolt/grubscrew that could move the back and front independently would be a revelation! Most of my workshop time seems to go into mucking around with calliper positions!

Like these?

Dominion A4 Brake Kit

Hayes did this a few years ago, see the grub screws on the side of the calipers; https://hayesbicycle.com/collections/brakes/products/dominion-t2-brake-kit

Surely it should be possible to design brake callipers or adapters to have some kind of micro-adjustment screw/mech in them to avoid the faffage of undoing the mount bolts and trying to adjust the position?

Cheap, adjustable: Pick any one.

Surely any adjustment will get caked and corroded, thereby negating their use?

It is pretty easy to adjust at present, and only two bolts…

When fitting new calipers, changing wheels etc?

I just loosen off the two bolts, fit a shim tool, squeeze the lever, tighten up the two bolts and remove the shim tool.

One of these actually…

Disc brake spacers

Its not something that should need doing unless changing wheels with slightly different disc spacing.    I much prefer IS mount as the caliper is fixed then.  But even with post mount the best setup is to centralise the caliper first then centralise the pads in the caliper.  That should then not need touching until the pads are replaced.

if you constantly have to fiddle you will have a sticky piston.  the loosen bolts pull brake on and then tighten bolts method only works if both pistons are moving equally easily

Another vote for wee alignment tools here. Cost buttons, lower the faff massively

I’ve often wondered about something like that (micro-adjust calipers) but I agree, would probably get filled with crud. The caliper always seems to move slightly as you torque up the bolt!

I bought some of the metal sliver allignment tools but never seemed to get that great alligment with them.

I got these for my E4s though and they worked great – really quick to get fantastic alignment. Expesnsive for a little block of 3D printed plastic but worth every penny IMO!

Sometimes with some set-ups the caliper will move slightly on the last bit of tightening so those grub screws on the Hayes caliper are a great idea, as long as you use bolts with a small unthreaded section under the head it should give perfect results, using stainless steel grubs won’t corrode and crud can get in through the slotted caliper holes anyway so that’s hardly an issue, the shim over the rotor solution isn’t 100% fool proof either as the rotor can flex, so if you’ve got a stubborn or slightly imperfect caliper or mount it can still uncentre itself.
I think I’ve seen someone do a diy grub screw set up with their Hope calipers on another forum, maybe Hope should follow Hayes lead.