HA Yellow with external Zigbee

Hello,
some months ago I migrated from a RPi 3 with a SONOFF Zigbee dongle to HA Yellow. Which was a major improvement.

Since then I have added a lot more ZHA devices (ZHA now has 113 devices) but I see sluggish behaviour for some devices. I was wondering if this might be due to using a built in Zigbee coordinator rather than a dongle with a bigger antenna.

Would using the SONOFF coordinator help with network performance?
Can a HA Yellow use an external zigbee coordinator?
What’s the process?

regards
Steve