Is it safe to skip the initial block verification at startup?

The longest step in bitcoin core initialization is "Verifying last 6 blocks at level 3". The number of blocks checked at startup went down from 288 in 2014 to 6 now. Therefore, in order to speedup bitcoin core initialization I am thinking about lowering this number further to 2-3 with the checkblocks option.

However, I wonder how risky this is? In case bitcoin core shuts down incorrectly, isn't it unlikely that all the last 6 blocks become corrupted? Isn't 2-3 blocks enough?

I mean 6 is kept so that the current utxo set is validated again as 6 confirmation is the official confirmation required. So 6 is fine but you can keep 2 - 3, I don't think there is any security trade-offs for that!