it's a shame that electrum doesn't offer 24 word seeds by default, I know it's possible by entering commands in the console but I'm afraid of compromising security, or doing something stupid, it's a bit off topic but do you know if they have an update planned?
I am not aware about a potential update from Electrum's dev team
But on linux you can just go with the following command :
electrum --offline make_seed --nbits=256
I don't see any security risk regarding to this one, if you trust your computer and OS, and do it offline ; everything should be fine