All my friends have been doing the same. The bloom is off the rose with Bangkok Bank and their recent frankly sometimes bizarre requirements and policies apparently NOT demanded by Immigration authorities. For this reason and others, many are opening a second or third thai bank account out of an abundance of caution.
ALWAYS have a "Plan B." And in today's crazy geopolitical environment, Plan C and D is a reasonable precaution.
If you're lucky, 30 minutes at immigration to get the necessary paperwork, and 30 minutes at the bank. Walk out with a bank book, Visa debit card and working ap on your phone.
That's how it went for me a couple weeks ago at Kasikorn Pattaya Central Festival. I'm on a non-immigrant O retirement Visa. So much faster and easier than opening my Bangkok Bank account 5-ish years ago.
Are you planning to walk/swim back to your home country when you're finished, or might there be some travel expense involved (flight, hotel, land travel, food etc.)?
For an established and frugal long-term expat it CAN be enough, but for someone coming for just a few months, 1000€ / month is definitely on the low side. Better to budget at least 2K/month. You can always just not spend it if it turns out to be more than you need.
If you say so, Captain Thailand. But some of these agents have been in business for many, many years. They have hundreds of thousands of clients, some for decades.
If they misrepresent or lie, they will instantly lose all that good will painstakingly gathered.