I used it on some beech veneered MDF tables I built for a shop.
All of the edges were mitred so I can't offer any insight into the effect on the edging, but the veneered surfaces all worked well, with a consistent sheen level and no lifting of the veneer itself.
It's not the oil affecting the glue, it's the glue affecting the oil. Here's what I mean.
The veneers you're dealing with here are about 0.6mm thick, then they're finish sanded which will bring them down to about 0.4mm or 0.5mm. The glue used to lay the veneers is a UF glue, which is pretty impervious to any finish. But on some timbers, Sycamore being a prime example, the glue tends to wick through the veneer so in patches it will be barely below the surface. When the oil hits these patches it can't penetrate as much as in surrounding areas, so the result looks blotchy.
It's onely a problem with certain timbers, the good news is Beech isn't one of them so you should be fine.
Just noted your reply in this thread. You mention that some veneers are too thin and the species. I am reveneering a table with 1.5mm cherry veneer, is this one of the species that would be safe with osmo poly?
I've never had any problems with American Cherry veneer, either 0.5/0.6mm commercial Cherry veneer, or thicker highly figured Cherry veneers that I've made myself on the bandsaw.
However, I'm intrigued by your comment that your veneer is 1.5mm thick. That's an odd thickness, too thick for commercial veneer but not quite thick enough for constructional veneer.
There is a general consensus that the maximum thickness for veneers that are to be laid on a man made ground is in the range 1.0-1.5mm. However, to go up to 1.5mm you need a moderately soft timber like Cherry, if you tried 1.5mm with say Rosewood you'd be running the risk of micro fracturing spoiling the result.
One other point, many finishers don't like old based finishes on Cherry because of blotching. Personally I'm less concerned because Cherry patinated really quickly, especially given some sunlight. So give the piece four to six months in a south facing room and, even if there was an initial trace of blotching, it'll quickly become invisible.