Our previous boat
was a FP Maldives
with low aspect ratio keels. It was moored on a half tide swinging mooring
for 7 months a year in a fairly exposed location, taking and lifting from the bottom 4 times a day. The bottom was mud, gravel and the odd brick and rubble. Did that for 11 years or so. Initially, I planned to put SS shoes on the bottom of the keels, but decided that as there was so little wear on the keel
bottoms, it wasn't worth it. The keels were foam filled grp, nothing special.
For the occasional deliberate grounding in controlled and presumably benign conditions, I see no reason to do anything other than be careful. Of more concern to me would be taking the ground on a hard substrate such as sand. Even in apparently sheltered locations, any wave or swell action can cause considerable pounding for a sustained period during liftoff and landing which can easily be damaging.
The difference on our mooring
was that the substrate was reasonably soft such that you could not feel taking or taking off the ground, sometimes with embarrassing results when you realise you have to negotiate 50m of mud to get ashore.