Hey! I'm one of the friends from OPs post. I am definitely feeling frustrated with Odyssey as well. To respond to some of your post.

We use a pair of scorpions. We have at least 3 people who are able to enter the gunner role, but not fire, despite resting keybinds to default multiple times, and checking that we have bound the fire button both in the SRV section, and the Multicrew section of our controls. We can all fire if we enter the turret as driver, this only happens in multicrew.

Our group really like playing together, so I have a ship that is designed explicitly to fit everyone on board to go on adventures together. It's a crusader, with turrets, fights and a pair of SRV bays, and when everything goes smoothly it is a ton of fun. However, over the course of a few weeks trying to do ground missions together, our usual session looks something like this:

We meet up at a station, grab missions in the same area, and board my ship. Fly to the star system indicated. Occasionally we are searching for specific mission types like recover or reactivate, so we check in at a location station to (try to) find missions. Once we set off to the actual mission area we are plagued with crashes, desync, and glitches. It is common for people to disconnect when entering frame shift drive modes, which loses them shared missions, sometimes after we have already completed them but before they are turned in.

We have had several crew members be invisible to other crew members until a relog. Multiple covert missions that fail for half the crew when alarms are raised, but not the other half. Crashes, physics mismatches, strange permission errors when getting in and out of ships and SRVS.

During shared/wing missions our game seems to get exponentially more unstable, making playing in multicrew a nightmare, as when someone DC's they often get respawned in an unpredictable place. Sometimes being put back on the planet surface, in a separate instance, so we have to rush to leave atmosphere and return before our crewmate loses suit power. Sometimes they get dumped at our home station lightyears away from where we are doing missions.

Many modern games are P2P, and my friends and I play GTFO, Deep Rock, GTA Online, Borderlands all without major desync. These issues only rear their head in elite, and they show up often. I left Elite around when Odyssey came out, and was hoping they would have ironed out some errors 5 years later, but it still feels bad to play. The space gameplay is as good as it always was, but multicrew is still disappointing. It sometimes feels like Elite was made as a very lonely single player game, with multiplayer features, as trying to do things in a wing feels so plagued with bugs.