3/4" is quite a bit to go.
they do make flange extenders that stack up.
Or the fluidmaster waxless seal is good too.
The toilet should be fine.
Yet another setting toilet / flange question, I did search the boards but didn't see this much gap covered:
ABS 4x3 closet flange is already solvent welded to pipe & screwed to wood subfloor. Installed mortar bed & tile around flange, resulting in finish floor 3/4" higher than top of ABS flange. After reading board realized I should have gone over tile, but now I'd have to cut pipe, shim & reattach.
Toilet is Western Wentworth 1152 / 1-piece low-boy (link) , given as gift.
1. Any bad comments on toilet?
2. From the boards, it seems I can set the toilet with an extra thick wax ring or two rings doubled up. The plastic funnel seems to be discouraged. I've also seen mixed comments about doubling the wax rings. Am I in trouble by trying to make up this distance and should I go to the effort of resetting & shimming the flange?