Fix reflection warnings

Sigel reflects quite a lot. Some reflection warnings seem a bit tricky to get rid of, but could maybe remove at least most of it.

No files, tests, or entry points are named. Start by locating Sigel's reflection-heavy code and reproducing the current reflection warnings, then determine which warnings can be removed without changing behavior. Done means the warning output is substantially reduced and the relevant behavior remains covered by the project's existing checks.

Written by the indexing model from the issue text.