This option works very strange and I can’t think of any appliance of this option. How exactly does it work ?
The thing I could really use instead of this strange subline factor would be quantization accuracy (in percents, values from 0 - 100%) so you can quantize your live recording but left some live feeling.
it approximates the delay of a note to the nearest value based on the quantization you set: a quantize factor of 20, will round the delay of a note to the nearest 8th of row (20h = FF/08h)
Ok, I get it now 
And what about quantize accuracy ? I suppose it isn’t hard to implement and it would be really useful for all people that record tracks.
what is the difference between the existing quantize factor feature and what you call “quantize accuracy”? I would see no difference, so I’m missing something
Let’s say I recorded this:
C-4 … … 02
C-4 … … 50
C-4 … … 40
C-4 … … 08
After I quantize this selection with subline factor 100:
C-4 … … –
C-4 … … –
C-4 … … –
C-4 … … –
(renoise move each note to nearest row)
Now lets say I have quantize accuracy set to 50%.
After I quantize this first selection with subline factor 100 and quantize accuracy 50% I get:
C-4 … … 01
C-4 … … 28
C-4 … … 20
C-4 … … 04
(each note is 50% closer to nearest row)
And with quantize accuracy 90%:
C-4 … … –
C-4 … … 08
C-4 … … 06
C-4 … … –
(each note is 90% closer to nearest row)
This way you can record a track, make it more in time but leave some ‘human’ feeling.
In Cubase it’s called Iterative Quantize:
“Instead of moving a note to the closest quantize grid position, Iterative
Quantize moves it only part of the way. You specify how much the
notes should be moved towards the grid with the Iterative Strength
setting in the Quantize Setup dialog.”
I hope it’s clear now
I see. You could maybe record with the desired quantize factor and then apply humanization using the advanced edit; the result will be even more human because advanced edit’s humanization has a configurable range of values, while the method you described has a fixed, not random, result.
Div or Sub and Mul or Add won’t work because div and sub will always reduce delay, mul and add will always increase delay.
And quantization should moving a note to the closest quantize grid position.
Same situation with recording with the desired quantize factor and then applying humanize:
When I record this note:
C-4 … … E0
— … … –
After I quantize and humanize this I will always have this note moved to next row with some delay added after humanize:
— … … –
C-4 … … 0F
It’s not possible to simulate result of iterative quantize and it still would be nice to have this in Renoise