We bought our house 3 years ago and it came with these beautiful, I think, Ipe flooring (correct me if I'm wrong). The problem with this floor is all the gaps which to me look like poor milling. See the pics below. The largest gap is on one board and is 3/16", the rest of the gaps range from 1/16" to 1/8". Humidity inside is 60% right now since its been insanely hot and humid here (normally mid 50% inside), I live in Ontario and have AC & HRV(new).

https://imgur.com/Zh8dPSM
https://imgur.com/n3tdGPx
https://imgur.com/4HNiLNL Biggest gap
https://imgur.com/aIVjZMq


Can this be refinished? I have seen how resin and sanding dust can be used to fill gaps, but is this too much to fill?

It looks like the flooring was not acclimated before it was laid. Can you see where the floor is fastened by looking at the tongue? If it is fastened well you may be able to add filler to the gaps. The gaps are close enough together that the T&G will keep the boards in alignment, still.
Do the gaps exist all year and are they the same size during the year?
Filling the gaps would take a lot of sanding dust!
Where are you located?

I’m in Kingston, Ontario
The gaps are there year round and appear to stay the same size. All the boards are nailed down wel except for the one large gap board. I could always add some finishing nails to add some extra insurance.

With wide gaps you may be able to nail through the tongue with finish nails or cleats. To reduce the chance of splitting the tongue pre-drilling is best. Depending on your sub-floor a nail every six inches is great!
The boards look flat so sanding will not remove a lot of the thickness. Wood flour from an Oak floor could be colored to match your floor to fill the gaps with a lacquer based wood patch like what Glitsa makes.

Floors in Australia sometimes have large gaps between planks. Mechanics there have used Sika II FB as a filler. It comes in a caulking tube, black color, and is applied with a caulking gun in the gaps. With a one week curing time it is ready to sand along with the flooring. It stays flexible and will never pop out like some floor patching material.