Visa Extension while applying for JFRV

I’m American, lived in Taiwan in the past, left for a few years, got married to a Taiwanese, we just moved back last month, and now I want to extend my visitor visa while waiting for my background check.
OK, the details:
I was here in the past for about three years. I moved back to America with my now wife for a bit more schoolin. She was studying for her Master’s, also. That old visitor visa expired a year ago. I applied for a new one, got it, and am now back.
So now I am on another 5yr 60 day multiple entry visitor visa.
My plan was to round up all the required paperwork so that when I arrive I could just do a single trip to the consulate and get a JFRV.
When I had just about everything done on my end, I went ahead and got a cheap ticket I found, still waiting for my FBI background check.
Now I am here, and my folks in the States received an FBI letter this week. It turns out my card was declined (long story short: lost my wallet, cancelled my card, then they tried to charge it). So it apparently took the FBI four months to tell me I had an invalid credit card number, but I digress.
I immediately sent back all the info to the FBI (they said they will hold on to my docs for no longer than 3 months, so I think they may already have it processed, or at least partly so).
Well, now my 60 days is coming to about the halfway point. I need to decide about when I should apply for a visa extension. I live in Taichung, so it will be a day trip for me.
Does anyone see any problems I will run into about getting an extension, or is it pretty straight forward? Like I said, I have almost all of the needed documentation (marriage license, certificate, all translated, medical stuff, pictures, etc.) so I can show that to the folks at TECO.
Also, should I apply for an extension a few days before it expires, or can I do it now and it will just extend from the day it should expire?
Oh, and one more note: I overstayed on my old expired visa twice before, but I had returned to TW multiple times since on that visa, and after it expired, I applied and received a new visa with no problem. So I am thinking that won’t affect my situation, but I really don’t know.
Thanks a lot, look forward to any help and tips.

EDIT: I do have my State criminal background check, but I am under the impression that I must have a federal one. Is that right?

Speak to the NIA. You will get 50 conflicting posts.

If your visa is extendable they should do it on presentation of your marriage license. That’s what they did for me a few years ago.

Will, they do it for you? I don’t know.

Take your documents and wife to immigration.

Thanks for the reply.
So I can go to my nearest NIA in Taichung to do it?
I thought I would need to go to AIT in Taipei.

[quote=“crybllrd”]Thanks for the reply.
So I can go to my nearest NIA in Taichung to do it?
I thought I would need to go to AIT in Taipei.[/quote]

AIT won’t do a thing. NIA anywhere can issue an extension if they are of a mind to.

Thanks a lot.
I will post back on Thursday after I talk to the folks at NIA.

Alright, that was easy enough.
I went to the NIA in West Taichung, and the gal there could speak English (!!!). I just showed her my passport, marriage certificate, and wife’s ID. She made some copies, I signed a paper and we were out within 5 minutes.
She told me to just drop in again if I needed another extension.
The extension was for 60 days that starts on the day my old one expired, so that was nice.
Thanks again!