One thing that gets a bit annoying is when you want to keep all your factories on repeat build, but also add in some other units that you do not want repeated. E.g. you are building asfs out of your air factories, but just want to build 2 or 3 t2 transports. To avoid accidentally building more transports than desired you can just add a ton of asfs after you queue up the transports, but it would be nice to have an option to add in some units that are only built once and removed from the queue so you don't have to do that. This would also be better because if you have factories assisting another factory, you can get those priority units out faster since multiple factories can build them rather than just one. So, say you want to build 10 gunships and then go back to asfs, you can just add 10 to the main factory and get them built more quickly from all factories assisting it, and then go back to asfs. (Yes, for larger numbers like that you can also just change all factories over to gunships or bombers and then change it back later, but this idea would be more convenient to easily get exactly the numbers you want very quickly and never accidentally build too many of something, or have idle factories, and with less apm.)
I am imagining just a separate hotkey to add these units that are not added to the repeating build queue. So, underneath the main queue there could be another non-repeating priority queue.
I can understand that this might be difficult to implement, and since it would just be a small convenience, it would not be worth expending too much effort to attempt.
Thank you