Hairline crack/check. Fixes?

I just glued up a hard maple breadboard and I see an incredibly thin hairline check/crack on the end of the board. Looking at the end grain view I see the crack is about 0.5 inches deep into the 1.25 inch thick board. Looking at the top i see the crack travels about 1 inch long. It’s (now) obvious the end of the board was checked and I didn’t catch it

It’s about 50-60% humidity here in VT. It’s not a dry state, so that’s probably very normal. I had the board in my shop a week before working with it.

I don’t even think I could get the thinnest feeler from an automotive feeler gauge into the crack. It’s barely noticeable…but I do see it.

I wouldn’t worry about it if the board for me, but this is a paid job I’m doing for a co-worker and I want to see if I can salvage this board. I don’t want to shorten the board because it’s just the right length that the buyer ordered and it’s massive and I have some raw material costs and time and effort into this.

I have thought of trying to do some spot application of CA to seep into the wood, but i’m not sure if that is a lasting fix. I also thought of using my router and a 1/8 inch spiral bit to router the cracked area and then make a perfect fitting plug and titebond III it in there.

What are other options that might be easier/better?

Thanks.