H0 is the inverse of the age of the universe, which means that it varies from day to day and is not a Cosmological Constant.
The author claims to calculate it from constants G, c, me, re, and α.
The attached python script shows that that is not the case.
I reproduced Kritton crackpot formula and calculated the proposed iSpace alternative.
I tried to understand
The paper doesn't tell you anything.