[macintosh-hd]

The way I set mine up is the Time Machine section of the drive has a quota capped at 1.5x the size of my internal drive, unfortunately you can’t edit quotas without formatting the drive. (Is there any functional difference between a quota and a partition then…? Weird…)

[Reason077]

Yeah, that's annoying that you can't edit quotas. But they are functionally different to a partition because the quota just limits the maximum size of the volume. If it's not filled to its quota, any unused space is still available for other volumes to use.