Net 7 is stable. But is not a LTS release, so you will have 6 months to upgrade to net 8 after its release (this Nov) compared to 12 months for net 6.
Normally I would stick with LTS releases. But as Maui is a new framework, I’d stay on the current version, especially if creating mobile apps, which change fast.
Also as it is new, I’d expect Maui for net 8 to have changes. You should expect to have to migrate code to the new version every year. As non LTS versions expire in May, you want to plan your yearly upgrades to complete before then.