[Motorola One Action Questions & Answers] arsradu:
Thank you for the confirmation!

Few mentions, for anyone willing to attempt this:

1. make sure you really want to do this, cause downgrades, while possible, are a different story. And can potentially be trickier to accomplish. Not to mention you can very easily lose your warranty by unlocking the bootloader, and brick your phone if you're not careful. Don't say I haven't warned you.

2. make sure you either use the updated script that tys0n provided here, or at least, make sure you're getting the correct script for your Android version. The commands are slightly different for Android 10, compared to Android 9. And while it will probably not cause any issues on its own, you will get errors for "file not found". Which, of course, is normal, since the files have been renamed. So you'll have to correct that (meaning use the correct commands/script) before rebooting your phone.

3. while it is probably recommended, in my experience, you don't actually need to erase userdata for upgrades. For downgrades though, you do. Otherwise you'll get into bootloop. You can always come back and erase it later, but why not do it properly from the first time?

4. do NOT (unless you really, really want that) use a ROM with a security patch newer than what you currently have. For the RETAIL versions, for example, do NOT use the QSBS30.62-17-2 version. That version contains the January Security Patch. And you're probably coming from a December security patch. It will make downgrading a pain in the a**.

Not a problem if you don't want to downgrade, but just a word of caution there. It messes up things like you wouldn't imagine, and for no particular gain! So, do yourself a favour and just stay at the same Security Patch (if you already have the January Patch installed in Android 9, I guess that won't be a problem since it won't be an upgrade), or, even better, wait for the official OTAs. But since you're reading this, you're probably already waaay past that.

5. the script already has an option for removing user data (factory reset). It's option W in the menu. :) So...you don't need to type that manually. But, of course, you can always do that, if you want. The script will do the exact same thing.

6. there is a very high chance that the new ROM will not come with services like: VoLTE, VoWIFI, Carrier Aggregation (2CA).

So, if you need/want those, there is a chance you're not gonna have them anymore, if you had them before. There are also users who reported they didn't have those services before, even though, obviously, the carrier supported them, but they do have them now. So...take that for what it's worth.

If your carrier doesn't support those, I guess you've got nothing to lose anyway. But if it does, and if that's something important to you, you might wanna refrain from upgrading in the first place.

7. while it will probably work, you might have reception issues (including WIFI). For example, your phone will not pick up your carrier or wifi signal as well as it did before. I don't think it will be that bad so that you won't be able to make a phone call or something, but you might see a slight decrease (I'd say about 15-20%) in reception. Again, it depends. But just putting it out there so you're aware of it.

If you still wanna continue on this journey, I wish you good luck and see you after the update. :)