live adjustments to PID roasting

[jkfrfr]

I'm looking for ideas with regard to making fine adjustments to temperatures while auto-roasting with a PID.

My current issue is that I'm following an IT (inlet temperature) background curve, and the resulting BT is a couple degrees too cool, so I miss my target FC time.

Here you can see the PID is following the red IT background curve. The blue BT curve starts to run a little cool past Dry End, with the result that FC happens about 30 seconds later than the target background curve. I'd like to make adjustments while roasting to help hit the target BT time/temperature.

The simplest solution is to bump up the background curves by one or two degrees in the Profile Background dialogue box. It works, but also moves up the BT curve at the same time, so I can no longer see exactly where I want the live BT curve to be. There is another possibility, using an Event Artisan Command 'adjustSV()', which does exactly what I want, but only to the current SV - as soon as the background curve changes the SV, the 'adjustSV' change disappears. Another possibility is to create IT SV events following the IT background curve, and adjust them as needed while roasting, but this is a bit more complicated and more work to modify my various background curves.

Are there any other ways to add +1 or -1 adjustment to the background curve or live SV?

[jkfrfr]

I found a similar question here: #1444

I had also considered varying the Lookahead, but the issue is the slope of the curve changes throughout the roast, so one would have to guess about how a change in Lookahead would effect the total temp, and then it would also continue changing. I think one of the above other solutions would be simpler.