RMC:- Yes, that is the case. If we still need you level at/abeam Kumil then we should restate that part of the clearance.
The reason for that restriction is for when the sectors are split and it brings you into the sector underneath traffic that is descending to FL190 at Avant and it gives the guy who's working the LL/KK I/Bs from the south something to drop on top of. In reality, those two sectors are rarely split, except when there's a flood of outbounds and inbounds at the same time. These times don't often coincide with KK arrivals through Gibso as it's mostly transatlantic and the odd Ryanair, except when our cousins to the south of us are on strike....again.
If you get a chance, come and see us and it'll make a bit more sense than trying to explain it on a computer screen.