We have a bad pattern in our codebase like this:

auto it = db_slice.FindMutable(op_args.db_cntx, key).it;  // post_updater will run immediately
if (IsValid(it)) {
   db_slice.Del(op_args.db_cntx, it);

This can lead to bugs, because in such cases we don't provide the expected object type to the FindMutable call, which means we can remove an object of a different type from the database. We should verify that everything works as expected in all such cases — and it's better to avoid this pattern altogether.