I've checked it out a few times over the years. See all the comments above.

Plus: Those sand bars and channels have an annoying habit of moving all over the place. They rarely look the same as they do on GE or maps.
Secondly, the currents on the running and flooding tides can and do create nasty chop and standing waves. Very similar to the long sandbar just inside the Shallow Inlet entrance where the strip is only flat for a hour or so each side of slack tide.
Next there are the locals in 'grey suits'...........!

. I have been surfing out those entrance sand bars and felt sh** scared and totally spooked! I have a couple of very mad mates who actually wave-sailed those entrances a few years ago and went back for more!

Many of the nice channels are next to islands or spits with tea tree scrub in them which blocks the wind.
The wind directions you would need are not that common. The course that you marked would need a very unusual SW to SSW and they are rarely very strong. That wind is also blocked a lot by the Prom.
OTOH:The opposite side of the entrance may have more potential as it would work in an Easterly, which in summer can get over 30kts quite regularly. It might well be worth a trip on the right forecast and tide if you are feeling very adventurous!

I spent quite a bit of time a few years ago exploring the Port Welshpool channel. I thought it had the potential to work on a Westerly with a run up to a Nautical mile long. As it turns out, the sandbar only comes out dry on the lowest tides with high pressures and an Easterly. As far as I can find out, it never gets dry with a deep drop off in Westerlies when the air pressures are much lower and the low tides much higher.