Thanks, Jesse.
I really don’t think this makes sense for non-qwerty layouts. Please reconsider this.
Qwerty
First, I’m all for the arrows being there on the qwerty layout. Let’s talk about the qwerty users. There are two groups: those who already know that cursor layout (vim users) and those who do not. Those who do are fine – great! But those who do not would likely find the cursors to be more intuitive if they were in a diamond or inverted-T pattern rather than a straight line. However, it sounds like you’ve made up your mind that the inline way is the way you want to go. (That’s more than fine with me, but I’m biased as a vim user.)
But now let’s look at alternative-layout users. I only have experience with Dvorak, so that’s what I’ll talk about.
Dvorak
I’ve asked in Freenode #vim and ##dvorak, and all users I could find who use Dvorak and vim (only a handful in the time I was there) do not remap their keys: that is, they use the Dvorak positions of hjkl to move around. I’m among them, as is @andre. I concede that though my findings were that 100% of vim/Dvorak users operate this way, my sample size is very small. (Someone else in the #vim channel commented that only brand-new vim users ever ask about remapping things, which suggests that we’re not alone, though of course it’s not evidence.)
What that suggests is that no (or very few) Dvorak users have learnt dhtn (their equivalent of hjkl) as left, down, up, right. (Unless they previously used vim on qwerty of course.) So if we split Dvorak users into vim users and non-vim users we have the former group who is very comfortable with Dvorak hjkl as cursors, and the latter group who would likely prefer a diamond or inverted-T shape on a single hand for cursors. Neither group likely wants cursors in a straight line on the right hand (dhtn).
Therefore having cursor arrows printed on R2C10 through R2C13 (and the cursors mapped there in the function layer) doesn’t make sense for Dvorak. I’d wager it’s the same for other alternative layouts.
Others
While typing this I had a response on ##dvorak from a Carpalx layout user. He says he still uses his layout’s hjkl positions (even though they are insane – “left” is in the qwerty ; position for example) in vim, and would also use them that way when playing Nethack (read: lots of cursor use, with both hands on keyboard). I think this is rather telling.
Proposal
I argue that if you’re going with printed arrows on HJKL in the qwerty layout, on alternative layouts the arrows should be printed wherever the HJKL keys are in that layout (and the respective default mappings should be there too of course).
TLDR:
Having cursors mapped to/printed on R2C10 through R2C13 does not make sense unless those keys are HJKL. The arrows should either be not printed at all (and cursors mapped for those non-qwerty layouts to an inverted-T or diamond shape on one hand) or they should be printed and mapped to whatever keys in that layout are HJKL. I vote the latter, at least for Dvorak where the positions are somewhat intuitive.