Thank you. It's good to be back.
Oh, and I remember what I was going to mention in my comment that bounced, which is a non-spoilerific thought now that you've seen Mobius 1 & 2.
Usually Stargate is pretty good about cleaning up really big loose ends, but there was an unexplored possibility left with Mobius.
We only have Daniel's opinion that the rest of the original SG-1 members were killed, so they could've been captured instead without breaking continuity. Obviously Ra can't learn anything significant from them or it would screw up the timeline, but you could posit that perhaps they ended up in the hands of another sytem lord, who would of course have to avoid further interactions to prevent timeline issues. (If he screws up the timeline, SG-1 never goes to Egypt, never gets captured, and he dies in a cell.)
So here's a simple stab at what's possible:
The original team is captured and Carter is thrown in a cell with a dying system lord who Ra is killing, but killing slowly through repeated torture. Once the system lord's host is beyond saving, the Goa'uld takes Carter as a host and they escape through the stargate, leaving the system lord's former host's body for Ra's guards to find. Everyone assumes that system lord died, and they never give Carter another thought (or SG-1, which could be included in the cell without a major change).
The system lord of course learns all that his host Carter knows, including the existence of the second gate in Antartica without a DHD, along with the ancient girl frozen there in the ice. Since Stargate Command only found the one girl before SG-1 took the Mobius trip, the system lord would be free to explore the ice and look for any ancients who weren't that particular girl. As already established, a Goa'uld can cure the disease that was afflicting the ancients, so he'd be free to thaw one out, take it as a host, and learn all the secrets of the Ancients - as long as he continued to play dead and stay out of the Goa'uld's timeline until sometime after the modern-day Mobius events are completed.
So that gives you an extremely powerful system lord with ancient weapons, and who has been upgrading those weapons for thousands of years, who has an incredibly intimate knowledge of SGC and SG-1 members, and who hasn't had to fight any other Goa'uld (all of whom assume he died at Ra's hands back in ancient Egypt). His existence is completely unexpected, and he could even be a drinking buddy or neighbor of some of the team members. He might've even used the knowledge he learned from the frozen Ancient to ascend and then re-materialize as a true human instead of a Goa'uld (and who really wants to be an aquatic parasite anyway?), so that the presence of a Goa'uld couldn't even be sensed.
Could be a good guy, could be a bad guy, but it would've offered an easy way to introduce a very powerful new character with a deep background story (and mystery, since he would know very intimate details about SG-1).
Frankly, once I thought about it for a bit, it seemed to have better potential than the Ori story, hopefully more on par with Anubis or Ba'al. There are all kinds of possibilities in the forgotten Mobius characters.