we have a discord server where you can probably discuss these things (https://discord.com/invite/4xsEsg2), if you dont want to join on discord you can talk about this on the category extension forum as thats where less competitive categories are likely to be added (https://www.speedrun.com/katana_zero_category_extensions/forum)
Go to the discord server (https://discord.com/invite/4xsEsg2 or linked on the main page) and just ask if anyone wants a race, someone will definitely say yes. If you want to participate in a proper tournament then you can try and organise one yourself and share it in that same discord server. Alternatively you can join a tournament someone else is organising, I've got one planned for around the next month and others might happen after that if you cant make it (they happen every few months or so keep an eye out).
Its broken with dpad only, that's why fightsticks don't work. if you use the analogue stick on your controller then it works, although i reported this as a bug a long while back so it should be fixed in the dlc update