Can you please allow me to dose a wee bit of tough love.
By all means, do your research. Devour every morsel of information and knowledge.......but......and this is a big BUT.....
you are not going to have light bulb moments reading stuff or taking someone else's ideas or opinions. The problem will be that at the time they seem like light-bulb moments but you will soon realize that it's not really the case.
The only way to develop your roasting skills is by your own resources - that means......try something, measure and evaluate the result, learn, adjust and then repeat the process - over and over 1000 times.
There is no gospel. No stone tablets from the mountain that enlighten one about roasting. It's an acquired skill inextricably linked to your device, apparatus or system. From there you will develop YOUR style......and over time your style will change based on what you believe is true.
I have a few friends (not in the social sense) that also own coffee businesses and they roast coffee just like I do. Sometimes, they are having a bad patch and want to bounce something off me.....but it's not helpful because their system is different, even if it's the same brand and capacity.......tis different in many ways either due to the flue design or other factors.
So what I say is this......there is fundamental logic and there is acquired skills or awareness. This awareness of how your system responds......what happens at various stages, it's not written in a book, or applicable to my own environment......it's unique to them, so they must keep notes, think about what they changed, what impact did it have and was is better or worse.
Simon, what you are asking for is impossible and I will tell you why.
Last week I received a fresh arrival Guatemala. I thought it was nice and within the expected specification - moisture, density and screen size. So when I roasted the first batch on Wednesday morning, I though OH YEAH, this is too easy, done it before 80,000 times in the last decade, around 1st crack instead of the RoR diving like most hard, dense Centrals, it actually spiked up and behaved in the complete opposite to what I was expecting. Yes, yet another WTF moment and another never take anything for granted situation.
This also happened on a Colombian that arrived into my warehouse in Dec 2016. It roasts differently to the other 6 Colombians I have. There are no visible signs, no metrics that I can measure which would indicate it would roast differently.
Simon, develop a process the involves what you see and what you taste. Keep meticulous notes (which I suspect would be easy for you
Don't be the follower that is influenced by internet knowledge as it will lead you down a rabbit borough to nomansland.
Learn the subtle nuances of what happens to various beans during roasting and then cross-check that with your taste. by all means, try different approaches if the recommendations are logical and possible, but you must understand the change and the effect at the same time.
I roast slow and I roast fast - never is it related to the bean density, varietal or any of the nonsense that is available on the internet.
Seek first to understand what your device is doing......not whether the beans are a factor - yes they will present a spectrum of challenges, but ultimately the process of roasting is relatively transportable across origins and varietals - it's not the massive, insurmountable difference that most people make it out to be (just more a case of too much stuff that people can't understand, or roasting systems that are not operating properly).