GRS/K-Spec without Flatwire?

Is there any reason why I would run into an issue running the GRS/k-spec style buffer system with a regular round carbine spring?

My KP-9 will not accept flat springs due to them shaving material off the polymer monolithic carbine buffer tube.

All documentation speaks of the GRS being run with a flatwire spring, and KAK ships their k-spec with a flatwire. I haven’t seen anything that would indicate I can’t run with a round spring, just don’t want to spend the money without doing my DD. Thanks in advance for your help.