I'm not a big proponent of using agents but in this situation I believe it's the wisest route. I've seen many posts in the past where people are exasperated after having gone to bank after bank only to be turned down every time. If I were you, I would hire an agent the day after I arrived. I hear it costs about 3K THB but I think it would be 3K well spent. If you are in Pattaya, I've heard good things about Mots Services and Key Visa. You can find them both on FB. Also, Bangkok Bank is one of the banks (maybe the only bank) that will receive foreign transfers above 50K THB and will document the transaction as income from outside of Thailand (this can be very important at some immigration offices.) Below is a screen shot from Wise (money transfer service) from when I send over my monthly pension. Details matter here and can be the difference between being approved or denied and ending up having to hire an agent to acquire you a visa, at a hefty price. Good luck!!
My wife's son manages 1,200 rubber trees. Last week he got 20฿ per kilo but the price fluctuates and the quality of the raw latex is a factor in the price as well.
I did mine in spring of 2020 and I didn't get my refund until October 2020. Of course CoVid was raging at the time and I believe it slowed down the already slow IRS.
My comment doesn't have anything to do with registering your wife with the embassy. However, if you and her are going to remain in TL (i.e. not move to the US) you may want to file for an ITIN (Individual Tax Identification Number) with the IRS, so that you may claim her as a dependent on your taxes and add her to a US bank account, if you so desire. It's basically the equivalent of an SSN for someone who does not have a "Green Card." It increased my tax refund by over $1,400 for 2020 & 2021 tax years.