Actually, the lack of ablation is because of using the chute to maintain orientation - the parachute has enormous drag and absorbs almost all the energy of re-entry, leaving very little required for the heat shield. Try a munar aerobraking return without using the chute (with extra reaction wheels and batteries to maintain orientation as long as possible) - it's fallen off stable orientation a bit too much each time for me (it seems to have to be exactly oriented retro for the HS to protect all the parts, but I didn't have a 'Lock Retro' capable SAS aboard when I tried this), but before doing that the ablative shield has lost 20-30 units. Had 3 failed attempts to aerobrake return from munar orbit because it's not aerodynamically stable, then tried a direct return with chutes staged before hitting atmo - the chute deployed and the craft pulled 93.6g when it popped (at least according to engineer). No problems, and that time the shield only lost 4 units instead of 30.
