What options do I have if my marriage visa is still under consideration before my flight?

Maybe when it was time critical using a visa agent would of solved your situation. Sure it would have been cheaper doing it yourself. When I got my first retirement visa I used an agent Everything was done in time because like you I was leaving the country in one month. Then on return you start process all over again.

You can get a reentry permit good to 27 November as attached

If it it’s not done change your flight or go come back and start over

You should have done everything by the book. It is a well known fact that when a 1-year Extension of stay permit is issued with the reason "married to a Thai wife", the extension will always be issued for "4 weeks under consideration", during which period Immigration is going to do a home visit, and they expect YOU and the WIFEY to be present! They will ask your neighbours if you really live together and if your marriage is real. Then after the under consideration period you can pick up the stamp for the rest of the 1-year extension. You are NOT supposed to do any travelling until you have been issued the full stamp, and you are not supposed to buy any re-entry permit, because ist cannot and would not be sold for just the 4-weeks of consideration period by any Immigration just because it is NOT part of the procedure . . . . the re-entry permit can however be had for the full extent of the 12-months extension - once you got it definitely issued!

Get the list of requirements from your local office, ask any questions of confusion here and then take all the correct paperwork to immigration once, a simple process.

Why dont people go into immagration and get this sorted? Instead of asking here?

You also need to factor in the home visit from Immigration during the under consideration period, you need to be available for that.

You can do a re-entry permit under visa consideration period, so your visa doesn’t get void. But have to get back before the Nov 27 for your extension stamp collection.

Speak to the immigration officer. You can buy a re-entry permit which would only be good for the under consideration period but now you have started a fast track process there's no guessing when that would be