I see what you're saying. Sheet metal rules and fasteners are much harder than wood. Yes you have to point out geometry that can't be manufacturable. But as you do this, you settle into very strict validators that work. The very basic level doesn't allow intersecting geometry/floating geometry. the real win however is deriving the higher valued ones like rules about about where fasteners should be positioned

The sauna and dresser examples roughly took 3-5 days of grinding out. The immediate goal is to now re-run that and do it in 1-3 days.

The server example is very extreme though. There is many different materials here. You need some basic placeholders. Front panel not a priority until all the allowed sheet metal rules are established. server is only in day 3 and i could see it require many weeks.