I suggested this back in 2005, and I bet someone has suggested it before me: https://forum.renoise.com/t/making-renoise-a-live-sequencer/16374
And you’re right zoner, it would be very handy when editing one pattern of a part that’s several patterns long. Like, you could loop the whole four pattern long chorus to get the “whole picture” while editing the end to get it just right.
And you could scroll through the pattern sequencer while the song is running and use RControl to quickly try out different arrangements… even better if it was quantized.