Confused on cove and bottom

[matt4x4]

I would make sure your cuts are very accurate, maybe make a cardboard template for any curves and get those nice and tight (within 1/8" of the wall), I would not tape anything to the side of the pool, this way, it can all settle freely without possible distortion or something sticking (and believe me, it WILL settle with the weight on the water).
However, taping your cove to the foam is a non issue and i would do that just so it won't shift when you fill.
I would not use acetone on the wall, it may damage the protective finish, but if you follow my advice above, I think this just became a non issue.
Tuc Tape (the red stuff people use as tail lamp replacement in the USA) works really well on just about any surface if you still need good tape.

[Cal_Newbie]

How much settling is acceptable on a pool...as it sits, we are within 1/8" all around.

Bob-

[matt4x4]

Depends on size, your's being 12' wide by 24' long, half an inch is well inside the limit for both directions, most say within an inch, visually, you probably want it to be somewhat less, 1/8" is great, i doubt anybody could get any more accurate. If everything is compacted the same all around, then your settling should happen pretty even, this means the whole pool will sink that settling amount, not just one end, so essentially, your whole pool may just sit 1/4 inch lower than when you first put it up.