My take on the same problem

[tectiv3]

Hi!
I've actually tried to do the same thing you did here, come take a look if you want:
https://github.com/tectiv3/PHP-LSP.tmbundle

I've been using it since then with a mixed success. My language server is intelephense in nodejs which requires to be restarted once in a while, but apart from that - Textmate now feels very modern and still so much faster then VS Code.