I see that I'm getting quoted around this thread and was invited to pop in for comment.

One thing that I think is important to keep in mind when interpreting my writing on roasting is that I run an unusually broad range of roasts with percent mass loss typically somewhere in the range of 12-22% and end temperatures generally in the range of second crack plus or minus 30F°. Plus or minus 40 as measured on my machines is where I consider the palatable range but I've only had a good reason to do something on what I'd consider the extreme edges in a production roast with very few coffees in over 20 years of roasting. To put that in context, 2C-40 would be 1C+10 and there's a very specific raw coffee vegetal that is always present below that temperature and always absent above it regardless of how you get there. That means that when I'm talking about dark roasts I'm considering that as at least 15F° above the start of 2nd crack and more likely 20-30. People who primarily stick to either the lighter half of that or primarily stick to the darker half of this might reasonably have very different views on the matter.

When learning about the impact of different kinds of timing variations, there's really no good substitute for being able to try lots of different roasts of the same coffee at the same time. I recommend starting with just a basic light to dark progression, and this is something that I do with every new coffee I bring in. But for timing variations, you can plan several batches of a single coffee with a baseline that's somewhere in the middle of what your machine makes easy and then within whatever ranges you're interested in exploring, try to do a batch that's faster in that range and a batch that's slower in that range (go for big changes at first) while trying to match everything outside of that range as closely as you can such that if you imagine the different roasts on transparent sheets you can shift them along the time axis to get those to match up before and after the range in question with the only difference being the range you're trying to change. (Typica has a feature that makes this kind of exercise easier, but in the absence of that you can work out the plans on paper.) Repeating those exercises with different coffees, different varied ranges, and different ending temperatures is tremendously helpful in developing an intuition for how to get from what you're tasting to what you think you could be tasting with a different roasting plan. Those broad strokes can then be refined with further consideration of rate curves within more useful constraints. Unfortunately that kind of personal training does take a lot of time, a lot of coffee, and a lot of practice and I can understand people not wanting so much "waste." Shameless plug: I'll be teaching a class at SCA Expo with a limited version of this exercise, no roasting, just tasting, but the roasting plans for all batches will be available. Another instructor is doing a similar thing more focused on sweetness at that event and that has previously been a very good workshop as well.

With regard to the slowness of my machine, this is true (except when I'm on the IKAWA which is much faster) and my advice for matching on a faster machine is to let the earliest part of the roast just be faster. If things are lining up from the initial color change through the end, all reasonable consistency metrics (everything except obfuscations like DTR) will match closely enough for whatever it is that I'm trying to get across.