So, been pool diving and open water diving since I started this thread and as suggested I loosened the straps and it is working much better in particular the frameless Hollis. The prescription mask is still a bit leaky but a lot better.
Though I usually keep clean shaven I have paid more attention to this. I also notice that despite tucking fringe hairs under the hood these have an ability to migrate and in mask clearing or mask swapping (was playing around with fit of both) to get under the mask skirting. Might be in need of a hair cut, me thinks in any case. I think it was this that was causing a fair bit of my previous problems and got me to erroneously go down the road of trying to tighten my mask.
Did slightly over do the loosening of the mask strap at the weekend when I did a backward role off the RHIB and the mask came away in my hand.