Hi Dave - I have not ridden the FR2 wing, so can not say precisely...
A friend of mine is getting an FR2 in a couple of weeks, but I havent got one.
I have 4 different Ketos wings, and a 5th coming up shortly.
And i find the strap plan is spot on like most people ride, and different wings as there is a slight difference in stance (balancing point) with some wings yes, riding strapless mostly you notice this.
The difference is really small though, and when you dont have a rear strap it should not matter.
Unless you prefer to ride really narrow stance of course, then your straps will be too far forward.
I ride really wide stance, so prefer the straps or feet positions to be even more forward (and rearward) than on the plan, on most wings.
Never more rear than the plan shows, thats for sure.
On a small board my stance is somewhat like this, maybe frontfoot a tad further rear on the big wide wings, but less than 5 cm difference.
And I have even wider stance on bigger boards.
Using straps my stance is slightly more narrow and rear than when strapless as you can move you balancing point a lot more, but a lot of time between these sessions so hard for me to say for sure what works for others.
Maybe not much help here, sorry...