Typical rule of thumb is to limit the repad thickness to 1.5xT. Thicker pads tend to have a "hoop" effect where high stresses can be developed in the "thin" run pipe at the edge of the pad.

I have used pads at 2xT (very rarely), but only after rigorous evaluation of the external loads and importanly the pressure loads.

I do not recall using pads on ELLs. Best to relocate support or use thicker ELL. Always been able to work around.