I had yello birch milled into HW flooring (3" width). The butt ends are not tongue and groove. the installer said he can't install it because the ends will buckle.

As I ask around I get different opinions.
Your thoughts?

The ends will probably need to be squared up but they dont need to be t&g. Most all antique pine floors are made this way. Just be sure to nail every end about 2" from end and go on with your life. If you really were worried about it a biscut joiner would be the quickest and easiest solution. Another option would be to groove all the ends so a spline can be put in.

There is still lots of floors milled that way. I'd get another installer just because.

Just an thought from past experience. I recall doing a wide plank Patina (now out of business) product that did not have T&G ends. They recommended gluing the end joints before nailing.

Yeah, that installer is an idiot, get rid of him. The glue wouldnt hurt but for 3" I wouldnt botherwith glue.