Tradfri Firmware Updates with Other Gateways?

Just bought a bunch of clearence tradfri stuff...

The WS GU10, E26 1100lm WS kits (so bulb and styrbar remote) and tretakt kits with the rodret remotes.

Not keen on how big the Styrbar remotes are but they didn't have individual rodret left, which is why I bought the kits that had them.

I have some OG tradfri stuff (larger OG White base WS GU10s, a couple of the 1000lm WS E26s, a couple of the old magnetic puck dimmers and a slightly newer plug and small square on/off remote (not the tretakt) and the original tradfri gateway... though once FW was released that allowed them to connect to a hue hub, they've been connected that way.

I assume I can connect this new generation as is to hue hub (or hubitat hub which I also have) without needing to update the firmware but I am wondering if I should update FW on them anyway for potential issues. Is there a recommended stable FW for these? And can I update the FW on these, I can't through Hue hub, but maybe through Hubitat hub or would I need to fire up the old Tradfri gateway to do so, and does this newer tradfri stuff work with the old gateway, I assume so, though I know the new matter/thread lines only work with dirigera hub).