I mentioned the Inspak case that @MementoMori put me on to (and I dismissed as being too small) but I was fast running out of options.
So I took a punt…
There is an X3 and an X5 version of this case, depending on which camera you have. I awkwardly have the Z3 
so rather than get an X3 and hack it to pieces I went with the X5 as that would afford me more room for the Z3 camera.
https://www.amazon.co.uk/Bestem-Aerial-X5-Unique-Hardshell-Waterproof/dp/B01J8CC5V2
This case is compact, it’s actually narrower than the DJI suitcase, but it is taller due to storing the drone in flight mode.
First things first, no case would be complete without a Titan Drones badge, right? 
Raised profile on the lid which actually looks pretty cool 
Incredibly, this case comes with straps on it, they expect you to carry this on your back like a rucksack 
They’ve clearly no idea how bad my back is these days so the straps got cut off pretty quickly…
There’s an earlier model of this case with zips, this is the later model with catches.
Note the coutour, designed for your back, but this actually works really well when being carried as your leg fits nicely in the gap.
I’m impressed with the build quality of this case too, and despite that it’s still pretty lightweight
Anyway, on with the photos.
Inside the case is the drone, in landing mode, with the camera attached
There is space for two remotes but as I only ever use one I have put the CrystalSky, it’s charging hub and a second battery for the CS in the other controller cutout. Thankfully the Inspire 1 charger also fits the CS hub.
There is no room for my Inspire battery charging hub though and the 180w charger brick does not fit either so they both stay at home on the desk and I just carry the standard 100w charger brick in this case.
You can store four batteries in the top, one in the drone and one under the drone, so six in all.
Inside the lid is four cutouts, each of which is capable of storing 4 props. Who carries 16 props?!
I have my regular four, and four spare, so I have an empty slot here and on the right is my soft case containing 8 x Polar Pro filters.
The case even comes with a gimbal lock!
But the lock is for the X5 and doesn’t fit the Z3 so I sourced a gimbal lock elsewhere for the Z3.
Here’s a hidden spare battery, stored under the drone.
The CS with battery fitted, a spare CS battery, the CS charging hub and lanyard.
So in summary it’s a cracking case, very compact and the only things I can’t carry are the 180w charging brick and the charging hub. No biggy really.
If I wanted to carry both controllers I’d simply put the CS back in its own case and carry it separately, again that’d be a rare day anyway.
So thanks again @MementoMori for the recommendation, I take it all back mate 