Nope - I haven't a clue either, and I've had enough conflicting advice to convince me we need a test, so I've set one up.
I've used an offcut of pale iroko, and from the left I have 3 coats of Osmo UV Oil, then one coat of Sikkens Cetol HLS Plus light oak stain covered by 3 coats of UV oil, and finally on the right one coat of Sikkens Cetol HLS Plus light oak stain followed by 3 coats of Sikkens Cetol Filter 7 plus light oak. The test piece is out in the open facing due south in full sun so we'll see what happens. I'll update the thread at approx 6 month intervals, or when I remember or when asked.
I've used an offcut of pale iroko, and from the left I have 3 coats of Osmo UV Oil, then one coat of Sikkens Cetol HLS Plus light oak stain covered by 3 coats of UV oil, and finally on the right one coat of Sikkens Cetol HLS Plus light oak stain followed by 3 coats of Sikkens Cetol Filter 7 plus light oak. The test piece is out in the open facing due south in full sun so we'll see what happens. I'll update the thread at approx 6 month intervals, or when I remember or when asked.