It kinda has that...
R1 Home
R2 Page up
R3 Page down
R4 End
That’s how it’s usually done. Or delete, page up, page down, FN.
As mentioned earlier, even though that's probably the most common setup, it's not the go-to for a lot of people. I find myself always gravitating towards split Backspace on 65% boards, and PrtSc, Delete, PgUp, PgDn is the only setup that makes sense for me in that case. So it'd be nice to have the option.
I'd be interested in adding an R3 PgUp and R4 PgDn to the base kits for use on 65% layouts like Tada68 and White Fox, but I suspect their absence is to keep the kit size and cost down. If you're unwilling to add something that layout-specific, would you be willing to consider adding a 1U git mod for R2 and R3? Then I could just use all 1U git mods in the first four rows of my rightmost column. The existing Git Base Kit already has enough 1U git mods for me to use in R1 and R4, but the only 1U novelty mods for R2 and R3 are from the Assembly Kit, which are instructions that don't really match the git theme. There are plenty of git commands that aren't in there yet -- how about cherry, reflog, reset, blame, or bisect? If you moved something from one of the larger keys, you could use "cherry-pick" (though perhaps its absence is a statement).
You base kit size isn't your top priority and you have removed ISO from the kit. You could add R3 and R4 page up page down. Alternatively, you could do git mods for those too.
Although I would prefer regular R3 PgUp and R4 PgDn to avoid having too much color and keep the set looking clean, I think this is an interesting idea that's worth exploring. It could be a reasonable compromise. What makes it work is the 1u R4 orange Add key that's already in the kit. That being said, I'd like to remind that the white up arrow would break color continuity in the Shift row with that setup (you'd have
Checkout ↑ Add), which I don't think would look so clean.
In either case, if kit size really is an issue, I think the 1u R3 Code key should be the first on the chopping block to make room for one of those two options. And if kit size isn't an issue — why not consider adding both options (all four keys) to replace the Code key? The 1u R3 colored mod could be used in its place anyway.
As for the legends on the proposed 1u R2 and R3 Git mods, I think
Reset (to match
Revert) and
Show (to match
Commit) would work. They're frequently used commands that aren't currently represented.
Now, an unrelated suggestion: have you considered using "Scroll" instead of "Lock" for the Scroll Lock legend, Oblotzky?