The block you're looking at is made from end grain blocks, so a block that thick isn't going to warp at all. Maple is dense & it's difficult to stain evenly. It's notorious for being hard to finish. I'd doubt an ebony oil would give satisfactory results. I've spent quite a bit of time trying various translucent black finishes over tiger maple and had the greatest success by shooting alcohol based dye finishes with a spray gun. It's possible that a piece that small could be finished semi-ok with a gel based black stain.
Michigan Maple Block Query
I am considering a Michigan Maple Block AJA02015 audio platform/cutting board, 18" x 18" x 3 1/2", to replace a shelf in my audio rack for supporting a DAC. The thickness also ideally raises the height of the DAC in the rack. My concern is that it is unsealed maple. Preferably, I would like it black or, minimally, sealed in some way, because the shade of the maple is something I can live with. I am looking for suggestions regarding this. Should I be concerned if left unsealed for this application or not? Thanks in advance.