I recognize this dilemma!
I'm a long time portrait photographer running two PGF 2000s, and since the original carts were low I've been running Ink Owl Inks. I had used these for some years prior in two Epson 7880s, with excellent results. The IO inks for Canon 2000s work equally well--excellently, and the price-per ML is very attractive.
I appreciate that the IO inks can be blended with the OEMs, seamlessly, with no color changes / shifts, and I have experienced no issues with permanence using (mainly) Epson Premium Pro Luster, which I have profiles for the Canon.
I consider the Ink Owl inks the full equivalent of the OEMs, based on my long experience.
Issues: you lose ink monitoring, so you have to learn to weigh the carts empty and full. This is a fairly trivial maintenance MO. I tend to check carts periodically, spot checking those which are used most rapidly--mainly, PB, Y, G, PG, and PM. I print a lot (sometimes several 100' rolls a day) and usually refill once every couple of weeks. Refilling is very easy and quick.
Feel free to contact me if you have questions. And no, I have no connection with the company (though they are really nice to deal with).
Cheers!