GermanyAlso regarding your question about a discord server: https://discord.gg/eUZH8cxh Also linked above in the game summary (the discord icon :) )
There aren't categories that you are missing, but at the same time i would be opposed to adding them since we already have too many categories for the active base of runners.
I think it would be easiest to join the speedrun discord server (if you didnt already) ( https://discord.gg/bKJ2sYCu ) and either ask in the #ace-combat-7 channel or message sanic in a private message.
Depending on your internet connection you could theoretically live stream from your ps4 to twitch. That would firstly result in a better video quality and secondly give you a recording (past broadcast archive). If several clips or bad quality recording would be accepted is a question for the moderators (superSANIC).
I think segmented runs are not valid but you can start doing individual level runs. (See here: https://www.speedrun.com/acecombat7/levels )
Just putting my thoughts out there - depending if you want to really differentiate the leaderboard on difficulty or not you might aswell "just" do a dropdown for the difficulties and only have the normal New Game and New Game + categories. That would leave the difficulty at the runners digression. I.e. Minecraft Java Edition did a similar thing for their random seed category where the difficulty doesnt really matter for the category so its just a dropdown on the run submission.
