Sublimation: Off-the-shelf blanks, or DIY custom items? ...

[webtrekker]

I've not really had any problems with the edges of the aluminium lifting, but I know what you mean. When I've printed and drilled a sheet I simply 'dish' the aluminium in two directions using the edge of my hand so that it's very slightly concave and, once the clock movement is tightened in place, it pulls the aluminium right up to the edges of the acrylic. This works for this size of clock but I don't know how larger sheets would perform if they were just held in the centre region.

It's great that you've got a laser cutter as well as a bender. Infinite possibilities!