Instance finder

I'm leveling 4 new toons on raf ,and discovered if my other half joins my grp with a toon the same level(also linked to my four via raf) before we queue, then I removed him from group once all inside the instance (not via vote to kick) then he logs his lvl 85 and I invite it.. we can carry on with the instance and he can even teleport in.. is this a bug or intended?

This way he's boosting my toons fast with no instance cooldown and I can grant his lower toon the levels. This has been working since the 20's.

People have been doing this for awhile now and I would guess it's working as intended.