Great article and well thought out ORM. I don't use JavaScript extensively and certainly not TypeScript, but TypeScript is obviously better than plain JS.
I ended up with the same issues in PHP. The existing PHP ORMs are all bloated and slow. So I wrote my own that includes Active Records and an Active Table class. I have also implemented migrations, custom fields and relations, generated table descriptions (no manual configuration) and a lot of other functionality.
You can check out the PHP code here: github.com/phpfui/orm
It might give you a few ideas for your library.