It's kind of amazing how just driving the track in reverse can turn one of my favourites into one of my least favourite tracks in the game. Though FIC Reverse actually has some components that are more engaging than the forwards variant - the S after the cave and the split paths immediately following in particular - I think its flow is worse and it has some terrain features that, while not an issue going forwards, make driving very unpleasant when going in reverse. It also carries over some of the bad things from FIC forward - the ridge in the centre of the tunnels at the start (except now you have to go over them in order to hit sets of boost pads), the lack of incentive to use the verticality inside the tunnels and the uselessness of the upper path in the canyon chief among them.
First off, the ridges in the tunnels cause problems in particular here: as you will generally cross over from the outside of the tunnel to hit these speed pads. The ridge can end up unsettling a car sufficiently to cause an accident or make you miss the pads. While we're in the tunnels, same deal with loads of unused space in there as FIC forward. Maybe some boost or item pads on the roof to encourage people to go up there?
Next, the tunnel exit: This section of terrain isn't a problem in FIC forward because you've got a nice wide area coming up. In reverse however the bumpy terrain here can REALLY mess up cars - tanks especially - unexpectedly, which will cause you to hit the rocks at the side of the narrow entrance. For Jugg and Dread, most of the time you can cross this flat out. Sometimes, you get unlucky, a wheel touches the ground before the others do when you go over a bump, the car rotates and bounces and you go straight into this rock: which is not only quite hard to make out against the other rock behind it, but absolutely launches you. Tempest is horrible over this section and is nigh on guaranteed to have an accident if you touch the steering. This is by far my biggest beef with the track, and may be singlehandedly why I dislike it so much.
Now, the paths in the lower area of the canyon are all reasonably balanced against each other. The direct route is slightly quicker but there's not excessive punishment for taking other options. However, this crest: can be very nasty. There are slight bumps on either side - the worst one being on the left, and you can end up crashing with little to no chance of stopping if you end up misaligned (which is very possible given how rough the terrain along the straight is). Also, as with FIC forward, the upper path is completely useless. It's a couple of seconds behind timewise and doesn't offer much in the way of powerups. Worse, the wallride path is unused but still present and represents a potential hazard. It's not entirely unlikely that a car can get caught on the edge of it here again thanks to how bouncy that path is. Like on FIC forward, it really needs some boost pads near the start and maybe an extra pickup to be worthwhile. I won't comment on the jump down into the lower paths that you can take, since it's always going to be very situational and never a go-to racing path.
The hairpin has lost the boost pads that were there on FIC forward, instead having one on the inside immediately after. On the one hand I quite like this, since it opens up a wider variety of useful lines. On the other, it removes the 'speedster helping hand' that the pads in forwards - placed on a line that's really awkward for tanks to hit reliably - provide. The pad on the exit of the reverse track's hairpin is fairly easy for all cars to hit.
The rocks on the right here: represent a dead stop hazard if you take this section even a tiny bit wrong - or get an unlucky bounce. Would be nice if they were smoother, gone or a shape that doesn't actively grab onto the car.
I actually quite like this section, it requires more finesse than its equivalent on the forwards version: However, it's very punishing to get wrong - especially in a tank. It doesn't take much to end up going into the blue structures since you're in the process of recovering from taking the S immediately prior, and they're another instance of getting immediately dead-stopped for a small error. I think it'd be much nicer if the nearest structure was removed, giving more time to collect the car back up in the case of an error without changing the dynamic of the split path when taken correctly.