|I'm currently calling this prototype "Quartz"|
I encountered this most recently with the silkiest bamboo yarn I've ever used, called SWTC Bamboo. This design is not yet published. I was not looking forward to weaving in all the ends, but the silky ends have stayed put so far.
My first choice for a project like this would be to rip out the existing row to the beginning of the row, cut the yarn, and reattach it without the mill-tied knot in it at the start of the row.
A possible alternative to ripping out the partial row is to cut the knot out of the yarn, then re-knot it a bit loosely, leaving yarn ends about 5 inches long each. I'd continue crocheting until the project is done, then deal with all yarn ends this way:
I've had good luck separating the plies of the yarn and weaving in each ply separately using a sharp needle so that one ply is threaded through the center core of nearby strands. I'd thread a different ply through different nearby strands, so that a thickened area is not created.
Another possible option is if the yarn can be felted. If it's at least 50% wool and/or cashmere or alpaca and not superwash, then it might felt. If so, felt-joining is a possibility, but I don't have much experience with that. It might leave a thickened area like the Russian join might. If it's felted together really well, it could be trimmed thinner, but might be a bit stiffer than the rest of the stitches. Depends on the particular project.
So far, weaving in the separated plies of the yarn ends with a sharp needle has worked well for me, especially with silkier yarns that would otherwise work themselves loose over time.
A special thank you to Anne!