AC30s are actually also quite neutral amps. Maybe in a vintage way so for a modern tone I will have more highs and less lows but for a vintage vibe I'll run it with everything on noon.
Creating IR's has a lot to do with "what do you need the IR to do?". F.ex. Marshall amps are generally quite bright f.ex. the JCM800 and therefore f.ex. the Pre-Rola Marshall cabs round the high end in a nice way and does what you need for a Marshall amp. Using Pre-Rola Marshall cabs with modern amps like a Recto f.ex. (I've done this in real life) requires you to try and tweak the amp to be a lot brighter than it normally is. So if you have an amp you want to use you should maybe get to know it a little bit. Is it balanced? Is it scooped? Is it bass heavy? Is it bright? There are actually quite many variations and obviously the EQ section is there to compensate for things but generally I try to get away with the least amount of tweaking possible. ... this coming from a guy who has owned several Mesa Mark series amps in his life which are notorious for being non-tweaker's nightmares.
I feel like this should be discussed in the next video and hopefully demonstrated as well.
EDIT: Advanced level: I would rather advice people search for the cab they want to use and then find the amp that goes great with it. That's how I do it.