Just don't visit the same countries all the time and get repeated SETVs from the same place. She may have a problem doing it for 2 years as that is probably 6 or 7 in 2 years, depending how long her holidays outside are. Just see how it goes. METVs would make a lot more sense for that length of time.
LOL Yes we are on the same page here. I wrote it wrong (corrected). No funds for a single entry. Only place that used to do multi entry for a Thai child with proof of the 400k was Penang. Not sure if that loop is closed already or not. I would get a single entry and then extend for a year with proof of funds for the child. Too easy as he is already the legal father.
Why do you need to get a year outside? Just get a 90 day and then extend it for a year when you get back to Thailand. Put 400k in the bank. You are already legitimized (which is the hard part). Then get a single or multi re - entry permit, if you want to come and go. Will be 5700 per year. 1900 + 3800. I realize you don't wan't to show proof of funds. But it is only 400k and you don't have to use it.