I’m looping a pattern. I’m going to recording some new automations envelopes for a filter. There is currently already a filter automation. I’m right click and hold the filter frequency slider and move it. During recording, new values and the old values are mixed (filter slider is jumping around). It seems renoise dont overwrite values, when the mouse is not moving. But it should, because i’m currently want to overwrite the whole automation in this pattern and i’m holding the right mouse button.
Renoise should ignore the values in the automation of the current parameter and just record and use the new values.
Dont found any option to archive this, not sure if this is by design.
If you right-click on a slider, you are recording that particular value of that current moment of that particular line where the edit position bar is currently at.
It does not “draw” an envelope for you when you hold down the right mouse button and lock the slider to a certain value. Renoise 2.8 never did so either.
If you need some kind of steady line to record “over” existing values you could hold down the ctrl key on the slider for fine-change and then move it up/down or left/right at a small pace and then the point will stick around close to the same value.
You could also edit the points in the automation frame by picking one with the left mouse button, then hit the left shift button and swing left/right in the automation frame removing all the points that you encounter on your way.
However using the shift key while recording to “erase” existing nodes on the way might be a nice suggestion. If you like, i can move this one to the suggestions subforum as this is at least not a bug.
I thought that would be the way to record automation. So it’s not supported yet, right? Too bad, i love playing with the xy pad to get Some kind of different result, which I wanna record. Messing around with effect parameters during a great beat often gets better results than manually programming them. Now I understand why Renoise always put the automation to point mode. I’m new in Renoise, sorry. Not a bug, but a feature request 
It would also be cool to be able to stream and record these types of performances to record enabled tracks as audio - Or at least record on the fly movements as automation.