Need mutlple tags (more than 15 in the same area)/multiple gateways

hi I have below questions on the use of multiple tags and gateways.
Scenes 1: I need to cover a very huge area like (1000 square meters) using DWM1001, i know i could use multiple anchors and only one initiator, mutiple gateways to release this function. however , there is one problem: sometimes there will be more than 15 tags inside the same area. if there is any method to solve this problems.
do i need to use different panid to establish multiple networks, but when the tag move from one network to another network, how can i update its panid to let it could join in the new network.

thanks a lot.

PANS will support more that 15 tags in the same area. The system is designed to share the slots/seats.