SQLModel is supposed to be the best of both Pydantic and SQLAlchemy, but by design
an SQLModel entity backed by a database table doesn't validate its fields on creation, which is the point of Pydantic.
I can't take a position without looking under the hood, but what concerns me is "SqlModel is both a pydantic model and an SA model", which makes me think it may still have the dynamic unintended-query characteristics that I'm warning about.
I seem to recall using SqlModel in a pet project and having difficulty expressing many-to-many relationships, but that's buried in some branch somewhere. I recall liking the syntax more than plain SA. I suspect the benefits of SqlModel are syntactical rather than systemic?
"Spaghetti" is an unrelated problem. My problem codebase was spaghetti, and that likely increased the problem surface, but sensible code doesn't eliminate the danger
[0] https://sqlmodel.tiangolo.com/