Firmware upgrade z-wave device from secondary controller?

I have gotten the updated Zooz ZEN26 and ZEN27 firmware which supports Central Scenes and now need to update about 10 devices.

Zooz provides a utility for updating and I also have the HomeSeer Z-flash utility.

I’d like to use the HomeSeer utility as it can connect to the SmartThings hub as a secondary controller. Also the HomeSeer utility can do batch updates.

My question is: should it work to update firmware from the secondary controller (i.e., without removing the device from the SmartThings Z-wave mesh)?

Yes, that should work just fine as long as you follow Z-Flash instructions for secondary controller application with SmartThings.