Was wondering if anyone else had run into this problem when placing taps.

As an example, I'll use 1/2".

If you are going to show a 1/2" x-body gate valve being threaded into a 1/2" gauge valve, I can't seem to place a tap unless there is a 1/2" pipe listed in the specs. 1/2" nipples don't affect anything.

Or, as another example, a strainer with a 1/2" drain on the bottom. I can't seem to tap unless there is 1/2" pipe listed in the specs.

If the 1/2" pipe is there, all is good. Taps work. No 1/2" pipe listed, the taps won't work.

The reason we don't want 1/2" pipe listed in the spec is to eliminate users from putting 1/2" pipe where there needs to be a nipple.

I realize this is probably by design, for the tap command to work only with pipe, but was just curious if anyone else has run into as well.

Yup, ran into this with some specs that started at NPS 16" and went up large enough to walk through, but needed the small sizes to handle taps as pulled tees. I just made the small bore pipe as a separate entry in the spec with a description something like "FOR REFERENCE ONLY. DO NOT USE." so users would not pick it.