[Closed] Great North Trail - Forsinard to Altnaharra Advice

Hi All
In a couple of weeks we will be embarking on a JoG to Lands End trip taking in lots of byways and offroad sections.
The route has been planned using the Great North Trail, John Muir Way, GB Divide, Pennine Bridleway etc..
We will be on a pretty heavily loaded "gravel" tandem.

Just looking at the route from Forsinard to Altnaharra. I've read that the route around Loch Choire could be a fair bit of pushing with bog / hike a bike sections. Which could be pretty miserable with the tandem.

One option is to cycle round on the B873, which no doubt lovely would seem a shame.

A - is the route round Loch Choire as bad as it sounds?
B - Has anyone followed the Mallart River from Loch Choire up to Naver Forest and then followed forest tracks out to the road?

thanks in advance!