Chapter 5, Monday. Item investment values at 50, 50, 80, 73. Skill level 5, every 50 minutes.
Chapter 7, Friday evening, dinner with the late nazis. 80, 80, 102, 93. Skill level 6, every 25 minutes.
Chapter 8, Monday again. 95, 95, 122, 110. Skill level 6, every 7 minutes (6.25, really).
So, over the course of four days, Alec invested 20 times. When he can do two per hour.
Then, over the weekend, he invested 15 charge, 15 charge, 20 charge, and 17 charge, none of which are a multiple of 6, for a total of 67.
About 11.2 infusions. Which would take less than 90 minutes.
Separately, HP, Hit Points, is supposed to be how much damage he can take before it starts hurting his body, so I'm not sure why having low HP is causing him physical distress.
He one shot the UK not any continents and we pretty much know he didn't anyway because ward directly shows Africa and America to still exist,
Earth Bet was not the only place he went. He kind of went on a multiversal tour of destruction for a few days, and then did a lot of world hopping while thoroughly pissed when fighting Khepri. I'd have to check on the hands around throat thing and need to sleep now, but I suspect she forced him to dodge with Flechette.
The only exception to that is the UK because it's where Kevin Norton lived so he gave them a sudden painless death.
Kevin Norton was already dead by then.