Look for "Relation Modifiers" at https://guide.taskpaper.com/reference/searches/. I think you're search will work as you want using:
@gm2 <[n] 50
In TaskPaper 2 all search relations were string based, but with modifiers they can now be string, number, or date
This is trickier. The underlying issue is that TaskPaper item attributes are now stored as a key/value dictionary. So can't have multiple keys with the same value because one would overwrite the other. Some options to encode TaskPaper 2's
@a(b) @a(c) would be:
three @a-b @a-c
For the first example to search for a specific value (for example "b") you would need to enter:
@a contains b
Unfortunately you can't just click on a "b" value to generate this search.
The second encoding makes it possible to just click on value to get the specific searches that you want, but unfortunately makes it difficult to just search for all
@a. You can do it, but would need to type in a regex like:
Generally the search engine is much more powerful in TaskPaper 3, but you've run into the biggest weakness vrs TaskPaper 2. There's now yet a good way to associate multiple values with a single tag.
I think the first encoding i.e. (
three @a(b,c)) is best long term, and I expect to build in support for it eventually. But it's not something that I'm actively working on at the moment.