I tried playing around with a few more parameters. In here, you can see that I have two emitters, one for the trail, one for the text object. The only moving object is the trail, where it will continually pull out as the text object is stuck on birth and fixed.
It seems it only seems to flicker at the very beginning of the animation, and I still can't figure out why. If you let the animation run for any number of frames afterwards, it seems fine and as intended. Is there something i'm still missing with this setup?
I also added a turbulence modifier and that seems to solve the problem once the strength goes above 5. I'm not sure what this tells us, but I'm still uncertain if it's the setup, the sweep effector, or one of the trail / generator objects not interacting in the way I wish.
2020-06-17 x-particles Typography Play.c4d