[tmtvl]

Org Babel is really nice, but it doesn't really solve the problem, rather it sidesteps it my giving you the option to edit a block of code in a dedicated buffer. I don't know how well that works with LSP (I don't use LSP) but it does allow you to make full use of SLIME.

[ParetoOptimal]

lsp-mode does support tooling in source code blocks without opening it in a dedicated buffer by creating a virtual one backing it.

See https://emacs-lsp.github.io/lsp-mode/manual-language-docs/ls...