Flange question

The 3 inch PVC waste pipe below my toilet is about 1.5 inches below the floor level (23/32 floor, plus thinset and 1/4 Hardie backerboard. Flanges at Home Depot and Lowes designed to slide down outside of the 3-inch PVC piple only reach down far enough to cover less than 1/2 inch of the pipe. To ensure a good fit and PVC bond, how much overlap do you need between the flange's downward extension and the pipe? (I am thinking at least 1/2 inch, preferably an inch or more). If so, where can you purchase a flange that extends downward further? The only ones in the big boxes that are long enough are the type that are inserted into the pipe and are sealed with a gasket. I think I would prefer to avoid those. Sagacious advice is welcome. Thanks.

The proper solution is to fix the height of the pipe.

You could probably get by with a 3x4 long pattern flange, which you should be able to find at a plumbing wholesaler.

Glue a coupling onto the pipe, (cut the top end off if it projects above the floor", then insert a "spigot" flange into it, (cut it off also if it is too long).