You can get this effect by using the overall time signature you need (such as 7/8) and then using beams to show the rhythmic groupings you want.
BUT it seems like you are talking specifically about how the time signature is displayed. For example, the one you mentioned would look like this:
This is not necessarily standard notation, but it is used sometimes. We would consider it but because you can already get the music to sound and read in the way you want, in the most standard way, it may not be a priority for us.
Please add more detail in the comments so we can understand what is more important to you: the way it’s displayed (we don’t already do this), or the ability to write the rhythms you want (we do already do this).
The code this site uses doesn't understand the quarter note, so that box was a quarter note.
We have overhauled our Search option! Read all about it here: https://notes.noteflight.com/noteflight-improves-search-features/
Note: we have not yet implemented all of the ideas listed here, but many of them are still in our future plans. Stay tuned.
In the meantime, enjoy the much-improved search functionality!
I agree with you fully. I would give you 3 votes, but I only have 2.
It just doesn't sound like an alto sax.