I honestly don't know if the planning has loosened a lot since I last looked into it, or whether you're mistaken.
My understanding is as follows.
You don't want to be rooming accommodation because you're not zoned for multi-tenancy, so you want your tenants to be "tenants" (per the Residential Tenancies and Rooming Accommodation Act 2008).
But the exemption for part-occupation of a premises - whereby they can be "tenants" rather than "residents" - only applies if you let out 3 rooms or less, per s 44(1)(a)(ii).
Therefore it seems to me that your only legal option is for them to be classed as boarders or lodgers, in which case you can't have them on leases, and also, I think that'll be hard to establish without them having access to the whole premises, and with them having their own kitchen.
I also didn't think you could rent out a granny flat separately to the main household in Queensland without approval for multi-tenancy; you could only let members of your own household - e.g. extended family or a friend - live in it, but they couldn't be on a lease agreement.