QupZilla settings getting overridden

I'll say right up front that I'm not sure if this is a PA issue or an issue that I should raise with my favourite lightweight browser folk.

If QupZilla portable is the default browser and gets called by another prog it appears to forget that it is a PA.

The parallel with the much better understood FF is that a new profile gets created e.g.
C:\Users\ABC\AppData\Roaming\Mozilla\Firefox\Profiles\XYZ.default
which can safely be deleted and the next time FF is started one has one's PA FF profile in use again.

That doesn't seem to happen with QZ, where (I think) most of the profile data is in a much more compact set of files and the bit I'm interested in maintaining seems to be inside session.dat of which 3 generations seem to be kept and are easily lost by foolish restarting and wondering "where did the stuff I had before go? Ooops, I'm an idiot, I just overwrote it by restarting to see where it had gone, ever diminishing circles, etc"

From the PA POV shouldn't the session be left in the place it came from? i.e. isn't this one of those cases where the PA method of moving the profile from Data to App and back again is actually misguided and and makes things worse not better. QZ is, after all, natively portable and should be f**ked about with as little as possible.

The PA way is good but not perfect.