wrote

Fridge door plastic liner has 2 little moulded in rectangular
blocks that support the milk shelf. One has sheared off, leaving
a flat surface with foam exposed. The plastic is very thin, I'm
surprised it didn't snap off the first time it was loaded.
What if anything could I do about it?

I'd try Sugru.

In fact I have a similar problem with my vertical freezer.
It has roll out bins and the front left hand rail on the
second shelf has had the pin that attaches it to the
wall shear. Havent gotten around to trying it myself
yet tho. Have bought the Sugru.