In terms of grids, 4pt grid and 8pt baseline seems a better combination (or 5 / 10 as evangelized years ago by https://guides.area17.com/design-techniques/#grid).
8pt tends to be too large as a snap-to-pixel grid dividend for cross platform applications, plus it makes sense for the baseline to be a multiple of your grid unit.
I'm doing a lot of work on typography and vertical rhythm right now for my framework. The move is an 8pt element grid and a 4pt baseline grid for our products. This is interesting. I'll take a look at this.