Few months ago I extended my e-ITAS sponsored by my Indonesian wife , and yes , Immigration asked for the guarantor letter , but it is just 1 more (easy to get) letter .
In the E31A Visa request situation , I think now , the Indonesian spouse does not need to register as a guarantor , which is a bigger difference (in accordance to the Law) .
Anyway , I think this subject is not important/effective because in more than 20 years reading related forum almost everyday , I never heard of a sponsor & guarantor who had to be held responsible for his/her sponsoree's/sponsee's debt or deportation .
My former Retirement KITAS's sponsor lived in a different city , we never met .
I am/was sponsored by 2 wives (in different times) , but in both cases I am/was the one responsible for them .