Alright, alright. I'm trying to shed some perspective on you and you're hell bent on these micro calculations
You've determined it takes 1600 calories above your maintenance levels to build 1lb of muscle but somehow it'll take 3-4yrs to gain 12.5lbs to hit your genetic limit. (I've read it is 2500 calories, but I've also read many other numbers so we will use your 1600. Personally I just use it as a rough guide and adjust based on real life experience that I'm trying to pass on to you but nonetheless)
By your calculations you need 20,000 calories above maintenance to gain that 12.5lbs of LBM to hit your genetic limit and that'll take 3-4yrs to accomplish.
By your math that's only 13.698 - 18.265 extra calories per day above maintenance. What gives? You propose to eat 450 calories above maintenance when you start your cycle but don't mention what you've been doing up until now
For arguments sake (or for the sake of not arguing rather) let's use your micro calculations to your advantage. I'm not opposed to accurate data
Count every thing you consume so meticulously that you are within a half calorie each and everyday and pay close attention to how you specifically respond. Do that both while on cycle and off.
It's taken you 10yrs to gain 45lbs. Not all of that is LBM as it is clear you were going through puberty within the last 10 years as you grew 1-1/2". I'm sure there's a calculation somewhere to determine skeletal growth minus total mass = LBM gains. I personally don't know. I'm sure you can find something if you really wanted to fit it into your data
My point is you haven't seen much growth. You haven't answered what kind of gains you've made over the last year but I'm going to guess it wasn't much
Now, 6', 175lbs at 10% may look crazy impressive. You haven't posted pics. It's all relative.
IF you put on 10lbs after your cycle, that is HUGE considering. It's all relative. IF you pack on 22lbs no one will even recognize you including yourself
My point the whole time has been "relative". For the guys who'd need 3-4yrs to gain as little as 12.5lbs they won't gain as much on cycle. Of course if you finally decide to eat on cycle you can gain significantly
Again, who cares? You've got it all figured out mathematically tho..
So, consume your 450 extra calories the next 11 weeks and see what happens. See if your calculations are right. Maybe they are.
I personally have had the best experience with 500 calories over my theoretical maintenance calories. I gain steadily (natural), don't get fat, bloated and I don't dread eating this amount.
After cycle I suggest you pick a calorie amount you want to use and monitor what happens
By your theories. You'll want to use a maintenance level of calories and expect to rapidly drop 10lbs as you will be above your genetic limit which you cannot maintain off cycle