You only need to put in your first point of accommodation and every time you change hotels the hotel you are staying at will report you to local immigration.
If you rent a place then the landlord should also report you to immigration as a formality.
in all my time I’ve only been asked once and that was before I was married and I didn’t have a visa either. Now that I’m married and get a spouse non o visa I have never been asked as it’s not a requirement.
As mentioned previously you need to attach a PDF file of payment of accommodation or a letter from your landlord with a lease agreement. Just putting down an address or hotel is not considered proof.
You could fly to Singapore but would then need to apply for another COE to re-enter Thailand and do the whole quarantine or sandbox again once you return. Major pain in the ass.