It's not only the number of tables but also the number of columns
The table I take as an example in my tests has 200+ columns, which
definitely doesn't help.
I have also a lot of tables with high number of columns. The biggest
one has 254 columns. So what?
If we can come up with some patches, it would be nice if you could test them
with your workload.
When you are ready, sent me links to the pull requests and I'll test them.