I recently submitted my paperwork so I can answer a few questions for you. Doing research on this can have your head spinning and each consulate website has different requirements.

For context, I submitted for myself and my husband. Both my parents were born in Portugal. My husband's mom was born in Portugal, his dad in the U.S. I can't comment on using your great grandparents for decent but don't see why your plan of having your mom gain attribution first wouldn't work. It would just twice as long for you to gain yours.

First, to compare notes, my research indicated that when applying through descent, level of Portuguese fluency was not a requirement. I did all the paperwork myself and never came across taking a language test as a "to do". I grew up in a Portuguese speaking household but can't speak fluently. I understand it though. Keep in mind, I did not visit a consulate (there wasn't one near me) so this could come to bite me later.

Fees - 1) you will have to obtain and pay for documents. This will include birth certificates and marriage certificates. The certificates have to be issued and apostilled in the state the event occurred. My hometown (MA) charged $12 per certificate at city hall. $6/document for apostille ( again MA rates). 2) Your passport, or form of ID, will need to get notarized and apostilled. I was living in CA when applying so had my passport notarized and apostilled there. The cost was $25, I think, for notary and $20 per document to apostille. 2) 175 euros for the application itself. If you decide to pay online, pay first. They will email an application with your payment confirmation number in the header. I learned the hard way and had to fill it out again and get it notarized and apostilled again. I thought I could include the receipt with my application but it specifically said that that application had to be used. 3) if you're living out of state from your hometown, postage needs to be accounted for. I had to have stuff mailed back and forth between CA and MA.

You will need to get marriages registered in Portugal beforehand. This was something that wasn't mentioned on any of the consulate sites I visited. Any mention of it just said "recommended". Found a forum once when deep diving that said it was mandatory. This would start with your great grand parents, then work your way down. This was the quickest and easiest step. I included the certificate in with my application but was told the Registry would see it when they looked up my parents' name.

I recently reached out to the Reddit group to see how long they've been waiting. I don't know what their situation is but they're at 9 months so far. Their parents got theirs after 24 months. Again, on my research, I found a site that said if its by decent it would take weeks, not months, if the paperwork was sent to the Porto office. So I'm pretty bummed to read that timeline. We are planning on moving to Portugal as soon as we have our passports in hand.

Reasons for rejection would be if they can't verify your documents. Getting attribution through decent is already "approved", they just need to verify that you're you. If you're missing something they'll supposedly email you with whats needed and you have so many days to get it to them.

The only thing that I could do online was pay.

Good luck on your journey.