Soft bathroom floor

I did it on the previous TT. Removed the toilet, cleaned it, needed to be done anyway. Sliced the flooring along the tub and cabinet, then rolled the floor back. Fortunate that there were some floor joists just outside the soft area. I cut out the rotted flooring, added a support, put a new piece of OSB/plywood in and rolled the floor back over it. Put a new gasket down and reinstalled the toilet. Everything I read said do not put glue onto the OSB/plywood because it will cause swelling. I cut pieces of quarter round shoe molding to run along the tub and cabinet to secure the flooring and hide the seams. Once done, nobody could see the repair. Not a hard job, took about a week of working during the evenings. Have made a similar repair just inside the door of the current TT. More difficult this time because of cabints and walls confining the work area. Plus there were no floor joists close by, I had to build a subframe, secure it to the trailer frame, then the fooring went in. Took a couple of full days and a few evenings this time around.