I've had my FM9 about 16 months, and here's where I'm at regarding the scribble strips.
They are useful when sitting on the floor programming with the front (top?) panel.
If I'm sitting in a chair, playing recreationally and noodling around with factory presets, I'll look at them to navigate between scenes or toggle individual effects on and off.
When I'm performing, rehearsing, or using one of my custom presets which is 95% of the time, I don't even look at them, nor would ever have the need to.
That being said, inverted or not, contrast adjustment any which way you like, they look terrible. Washed out, small print, mostly wasted space in the screen. And inverting them leaves a large light border around the text, making it even harder to read than the standard layout. I also am not in love with the switches themselves (I'm still reeling over being told to grease the electrical switches when I bought it), so a redesign of the whole module wouldn't upset me.
But the scribble strips are the least important hardware feature on the unit so if corners were to be cut, that's where I'd like to see it so cudos to whomever made that call to keep the target bottom line.