I've mounted lighting in all sorts of places on the 4 last tractors. On the ROPS was my least favorite spot.
1. Most of the night work is mowing. The lowest mounting provides much better definition between cut/uncut grass. The most useful ones are mounted in my grille guard. Yes, they stink for snow removal and FEL work, so I use the lights on the cab roof for that.
2. When I'm out at night, so are the bugs. With ROPS mounted lights, the bugs spent a lot of time swirling around my head. On one of the tractors I mounted the lights on the part of the FEL frame that remains when the loader is removed.
3. I wear glasses and the ROPS lights were slightly behind me. That created glare from backlighting my glasses.
The picture below is the current rig fully lit. Nighttime disappears around the tractor. For mowing, the best lighting is when I only use the lights in the grille guard and the low side lights (mounted inside the FEL frame tube). This setup would work on tractors with or without cabs. The bright forward facing cab-mounted lights add a lot of unneeded brightness, and the extra light on the hood is a bit distracting.
