Very interesting post @jaymorebeet!!! I've been to Japan once, quite awhile ago, but I've never heard of okonomiyaki .
It certainly looks like it would be tasty and it reminds me of what Japanese quiche might be like.
While your chosen sauce looks awesome, I imagine that okonomiyaki might also pair well with some good spicy dijon mustard or maybe even horse radish.
I definitely loaded some sriracha onto mine AFTER taking these photos. You're right to kick it up a bit - and i think wasabi in the mayo would work perfectly. Ah the littles and their sensitive tastebuds limit my spicy intake!