What are the document requirements for a Non-O dependent visa for a Thai child at Savannakhet Embassy, and is obtaining a multi-entry visa possible?

Nope, that is most definitely NOT possible 😮

Unless I'm mistaken, neither Vientiane or Savannakhet ever offered the year-long, multi-entry Non-O based on raising a thai child, 🙁 Didn't matter whether you had the 400K in a bank or not. That wasn't a category of Non-O visa they issued in year long/multiple entry.

When those two consulates went to the online eVisa system (like every thai consulate in the world is on now) the year long/multi-entry options were discontinued for Non-O visas based on retirement/marriage/raising thai kids.

You can get a 90 day single entry from them, by going to the eVisa online website and reading the requirements, going to Lao, applying by uploading proof you're in Lao (visa/entry stamp), the required documents, submit it online, get the confirmation emailed to you, then print that and take it to the consulate to pay the 2000baht in person.

There's no thai consulate in the world that issued year/multi-Non-O's anymore.. You can get that 90 day single entry, then take the one 60 day visit thai family extension at the immigration office where you live. That'd buy you 5 months if you can't meet the requirements to get the in country yearly extension.