Yeah, I’m definitely accustomed to that too! For years I did a lot of copy work for some really well-known jazz composers. I just went back and found some pencil scans from one of them using that sort of convention. Like everyone from that generation, the score is transposed (paying the copyist to transpose was a 50% premium), but his shorthand just drew the concert key at the top and the copyist assumed the correct key sig for each staff.
Here’s a snippet of a score with 4 saxes where the Bari part should be written in the Reed 2 part, even though it’s at the bottom of the section in his score. The written line should be in Reed 4 on Tenor. (Note copyback notation in Tpts too.)
For another example, here’s a particularly crunchy voicing where the concert Db in the Clarinet in Reed 3 is a minor 9th above the concert C in the Alto Sax in Reed 1.
I can’t remember if I made scores for these or not (this particular client was often parts-only), but if I did I would have fixed the numbering and placed everything correctly by player in the top example, with the Bari in the Reed 2 part, under the Reed 1 part in the score. In the bottom example, nothing would be moved at all and the Clarinet part would remain on the Reed 3 part, third staff down, even though orchestrationally the Clarinet is above the Alto Saxes.