As stated in title, would be really cool, if you could also just type /rankup and would immediately open a GUI, which would state requirements to your next rank, and what you have or haven't done yet, instead of typing: /ar check Starter (for example), then after ranking up, doing /ar check Intermediate (also for example) I would do a similar GUI myself, but I don't even have placeholders available to me :D

That's a good enhancement! I'm already working on a project like that for Autorank, but it's not finished yet. Keep following me on Discord and Spigot and you'll get an update when it's ready!