Problem details:
How do (or even can) I get around this error and edit in other gamemodes?

Video or screenshot showing the problem:
https://ibb.co/wNXgxhs

osu! version: Lazer (latest version)

You can't. This is something we'll have to figure out as devs, but given the many other more important priorities it'll likely be months to years before this will be looked at.

Oh. Sad. Thanks though