Just doing the front calipers on my 990.

It's all clean and ready to be re-assembled.
I have measured the pads and the inners have worn more than the outer on both sides - approx 0.5mm.

Should I swap the inners for the outers now (to even the wear) or fit back as before so the pads' wear pattern matches it's disc face?

Was once told long time ago to mark them as they came out and put them back where they came from - have always done this but not understood the logic.

Maybe due to wear pattern, keep them the same?

Prob overthinking it, especially with a .5mm difference. I would just change them all at once to new when 1 more gets too thin. Why/what were you cleaning the calipers for?

No worries with extra cleaning, just wondering. Just ride her nice shiny calipers and change out the pads at once when it's time.

Its a very good idea to clean calipers with soapy water and toothbrush. This insures that Calipers pistons are not sticking. Any sort of jobs like this around the bike also give you opportunity to find any issues which you would not know about until they fail.

The outer surfaces of the calipers are washed every time I wash the bike and the working parts get cleaned with brake cleaner and an airline and get a bit of silicone grease on the pistons every time the wheels come out for tyre changes. Never rotate pads. Each pad wears to match the surface of the disc. Changing them around means they've got to bed in again which dulls braking performance in the first instance and accelerates wear.

Got it.

Wash with soapy water? (Washing up liquid contains salt)

A method as approved by others in earlier threads;
1. Calipers off, pads out.
2. Pull brake leaver to gently ease the pistons to protrude further. (If not gentle, enjoy the piston install).
3. Clean pistons with brake cleaner.
4. Dry off with lint free clean rag.
5. Gently poor brake fluid over the pistons.
6. Push pistons back in the caliper.
7. You know if the pistons are suitably clean and lubricated as you have a devil of a job getting all 4 pistons to slide back in, as you push one in, another tries to pop out.
8. If the fun in 7 does not occur, push pistons in a little, ease out a little with brake leaver and repeat until you enjoy the fun of 7.
9. With all slippy pistons nestled back in the caliper, clean the calliper and piston area with rag sprayed in brake cleaner.

Job done.

Only do one caliper at a time.

Be aware of brake fluid levels.