What features would you like to see in Pixelmator Pro?
If I'm working with a 2x resolution image and I'd like to export for web at 2x and 1x, it would be far more intuitive to export a 1x and 2x copy (rather than 1x and 0.5x and calling them 2x and 1x). What I envision is one extra field in the export dialog to specify which copy your source image is. For example "the source image is @2x" so then the 2x export would actually export actual size, and the 1x would actually export at 0.5x. This would avoid having to rejig the suffixes (which currently don't save, FYI) and keeps the terminology as you'd expect.
For a start, suffixes should indeed be saved with each preset, so we'll take care of that in the next update. We'll also see whether we can do something with 1x and 2x for 1x and 0.5x, although it may potentially be a little confusing having an extra option to say the source image is 2x. In any case, we'll think about it!