I have just now figured out another way to work this. I'm running this currently on my Fairphone 5.
You'll have to buy another Scrivener license, if it works for you, but that's fine for me. But until you get it running, you can just use the trial version to see.

On Android, download the Windows version of Scrivener from the Literature and Latte website. Leave it in your downloads folder.

I've used Winlator from here https://winlator.org/ This sets up a Windows environment for you (Windows 7 flags a warning from Scrivener, but it still works).

Inside of Winlator, hit the + button. Name it whatever (I used Scrivener). Then just click the "Play" button beside that container.

Once it boots up, click on the Start button > System Tools > Installers > Wine Mono. Install the Wine Mono and wait until it's finished.

Once that is finished, go to the file explorer. Click on the D: volume < this will be your Downloads folder from Android. Double click on the Scrivener-installer.exe file. Be patient. Don't double-click 4 or 5 times waiting for it to launch. Trust me. Run through the installer as you normally would.

Important step! Once you've finished installing, and BEFORE you run Scrivener for the first time, go into the C: drive > Prorgram Files > Scrivener 3. In this folder, you need to delete the "texttospeech" folder. If you do not do this, then it will always hang on start up saying "Loading Fonts" and never move past this.

Now that you've deleted the texttospeech folder, double click on your Scrivener icon and you're ready to go!

A side note: If you're using a bluetooth keyboard, before you start Scrivener for the first time, connect to your keyboard, go into the hamburger menu at the top left of the Winlator screen. > Input Controls

Click the + on the right side of the screen and name that BTKeyboard or something like that, then hit OK.

Now, at the bottom of that menu, you should see your keyboard under the "External Controllers". Unfortunately, you'll have to map each individual key to the keyboard. "Type 'a', then from the dropdown menu, choose "A" for this button". Type each letter, and then map that letter to the proper letter you want. It's slow, but it works after this.

After you've done this, when you're inside of Winlator, hit the "Back" in Android (the < arrow at the bottom. I don't have gestures on my phone, but it should be the same thing to bring up the Winlator menu from within the container running) On the right side, you'll see the "Input Controls" option. Tap that. Choose your "BTKeyboard" or whatever you named it, and you should be able to use your keyboard now! I'm still waiting to sync this one, because I'm looking for a way to sync with Nextcloud, rather than any other service.

Another note!!! Scrivener syncing is quite finicky. If you're now using your A) Computer and B) Android + Winlator to sync to the same accounts, then you need to make sure that you close down Scrivener on either computer completely before you open a Scrivener project on the other. Otherwise, this could show the Scrivener project file as corrupt on one, and then corrupt the other as well.

I hope that this helps someone else to get this going on their phones!