What are the requirements for sponsoring parents to Thailand under a Non-O Visa, and how does a surname change affect the application?

Hi everyone, I’m looking for some advice and assistance regarding a Thai visa process.

My boss is a US citizen who holds a Thai Permanent Residency (PR). He wants to sponsor his American parents to live with him in Thailand under a Non-O Visa. He has already prepared his legalized birth certificate, but we have two main concerns:

1 Mother’s Surname: His mother changed her last name to his father's after marriage. Will this cause any issues during the application?

2 Marriage Certificate: His parents got married in France. If a child with Thai PR is sponsoring their parents, is the parents' marriage certificate strictly required for the Non-O visa application?

Additional Question on French Documents:

If the French marriage certificate is indeed required and needs to be legalized, how can we request it?

We tried applying online, but the system requires a FrenchConnect account, which we don't have since we are not French citizens.

If anyone has experience with this or any helpful advice, please share. Thank you so much!