Draft: Get rid of all swmr. This is shitty.

The 'swmr' is always a bottleneck.

Once processed the volume viewer tries to open it in 'r' mode but without swmr. So when we try to reprocess the 'swmr' is already activated and reprocessing fails.

So the simplest is to get rid of it. I think we can expect when nabu processes that no other file will try to access the file (for writting). So then this will simplify things.