I reset my achievements (in-game, not on Steam or anything similar). After doing 100% of everything—tons of planets, tons of other stuff—I was still missing the "All Research" one. So I started disabling mods a few at a time. Then I saw this mod. I disabled it, and sure enough, because I had started on Vulcanus, the "Unlock Vulcanus" achievement was missing.

BTW, do the devs know about this mod? Because as far as I can tell, unless you use mods or you're a veteran who knows exactly what you're doing, everyone is annoyed that we either need to waste hours getting everything into the rocket or, as the devs intended, start from scratch on each new planet—ruining everything you built before visiting said planet (again, talking about the no-mod vanilla game).

And who knows—if they find out about this mod, maybe they’ll realise how horrible the idea is of forcing everyone to start fresh, instead of just adding a “start from X planet” option. Hopefully, they’ll also remove the nonsense weight system and let us put stuff into the rocket like it’s any other container. But hey, 50 assemblers weighing the same as 25 uranium bullets sure makes sense.

Anyways, sorry for rambling on about the last part, I just can't help it since so many people are force to use mods to fix a core issue that could have been prevented if only the devs implemented a "start planet of chose" insted of creating a "weight limit" to force us to start "fresh"

I never considered the achievements when making this mod, I guess I'll have to remove/hide the starting planet one and add one in for visiting Nauvis.
Thanks for letting me know!

As far as the rest, I know a decent amount of the devs are aware of the mod (I actually playtested the beginning of Gleba with one of them), and while I agree with the sentiment of having it be built in to vanilla, I also understand why they didn't as the guy who ended up making the mod.
It's a lot of work to readjust everything to not have softlocks and still be fun, but there's a couple things that stand out to me that would make it hard to justify having it be a vanilla feature:

The planets have been designed to bootstrap off of with the technologies you already have unlocked to get to space, not from the ground up.
This requires a lot of shifting of things around in the tech tree to make it possible, which isn't feasible to do from a dropdown map setting after all the technologies have been loaded for a multitude of reasons I won't get into here.

But let's say it was possible hypothetically, and we can choose our starting planet with all of the tech tree changes and everything, this also forces any mod that wants to be compatible with space age to consider the alternate planet starts, as well as any modded planets that also want to have the option to be started from. That's a lot to ask from mod creators, as it takes a lot of custom changes to make the experience work.

I believe alternate planet starts are only possible in mod form, and while it could technically be an official mod, I think it works out better this way.
I agree with the desire to start on other planets - that's why I made the mod after all - but it would be hard to do it officially in a way that doesn't make someone's life a lot harder between either devs or modders, so unfortunately this is the way it has to be.

Lastly, thanks for playing the mod. It means a lot to hear that people who are passionate about this type of gameplay are still able to do so despite it not being official.