How well can the Gyan operate on the ground?

[MythSearcher]

That said: GBO2 is - to my best knowledge - not an official source for lore. It can offer ideas and speculation, but nothing that is truly factual to the UC Gundam setting. (The game has various lore errors anyway...)

Since the Beam Bazookas are designed for Rick Doms, which does not have a beam weapon connector, to use, they have their own generator and thus presumably can be used by any MS given they can give an IFF signal and is strong enough to wield it.(in Space, it only means slower aiming, in gravity, you really need to be able to wield it)
Gyan, also a Zimmad model, should be the most compatible MS other than the Rick Dom series since even the signal connector should be of the same format if they are not using a standard.(They are, since Doms can use Zaku machine guns)

[TDR-10M Thunderbolt]

Those are all true, but I wasn't discussing lore; I was responding to how Gundam Battle Operation 2 operates. And after double-checking, I can confirm that in that specific video game, the Gyan Eos does not use a beam bazooka as standard equipment nor as optional equipment. It carries Dom and Rick Dom solid-shell bazookas, and has a miniature beam gun built into its melee weapon.

On its own, this doesn't mean much for correct Gundam lore; GBO2 is not 'official' in this regard as far as I'm aware. I'm just explaining how it behaves in GBO2 since a few others mentioned the game.

[JEFFPIATT]

That is with mobile suit parts. Weapons are a different thing. Gelgoog and Dom/Rick-doms have no problem or issues using Zaku weapons. Since the Gyan has the reactor strength, it should be able to handle the Gelgoog's beam rifle.

The Zaku II weapons required a refit in order for the Dom and Gelgoog to use them. the handles had to be extended this is reflected in some of the "Zeon weapon kits" Bandai puts out for the models and the robot soul lines where the ZMP-50D 120mm Machine Gun included has two handles the classic zaku and a Dom one.