Not yet, though you can accomplish similar with freeform mode (if using Aeros standalone)
You can also achieve similar by setting the number of beats in the measure (the numerator) in the the time signature to 1. (E.g. 1/16, 1/8, 1/4, 1/2)
I do think there are some less than perfect qualities to using 1/x as a substitute, I think it can be harder to handle fast tempos due to our Loop forgiveness zone being close to each measure in the Aeros.
One major feature we are looking into pairing with AutoQuantize is the ability to have multiple time signatures per song (one per part). So you may get what you want soon, stay tuned, AutoQuantize is not far off!
Rereading what you read however, you want polyrhythms in the part at once? You can already do this by just playing in quantized mode and turning sync length and sync start off, this will at least quantize things to the measure.
Let me know if that helps!
Thanks