At the moment, the maximum number is 2, enforced by the engine. We added that as a way to get dual lines in the squadron, but we did not go so far as to do calculations of positions for any other squadron formation beyond 1 single line, or 2 lines behind the leader.
Viewing post in Setting Group In Lines
Good to hear. I already had the 2017 ready to upload at a moment's notice if it was still a problem, but it sounds like I can continue moving forward with 2019 for the x64 bit. The 32 bit still uses 2017 because Microsoft has deprecated XP support in the newer VS2019 toolkit (I think you can configure to continue using it, but it is more work than I deem worth the effort) and it is simply easier to keep using 2017 for those 32 bit versions because I want them to remain compatible for WinXP.
I did not have any plans to further develop that into other formations because I only added that for a specific request for dual lines from the ERAS originator; I typically don't make those types of changes unless either he asks for something, or I find bugs/flaws, or performance/efficiency enhancements that can be made.