...so I'm grateful to have my 32 mm tires...

Joining you on this. My rims are 32mm and 28mm GP5000S at 4bars fit nicely on them.
This is so comfy, and I can't notice any performance drop in my usual group rides, even the fastest one.
And after long rides I don't feel as sore as before.

unfortunately not available in my size M 54.....

Did they tell you if it will be available in the future ?

...I'm from Belgium (Brussels)...

Oh really... I'm just a few mm below on a map 

Sorry to hear that your frame cracked after using for so many years lol. No, we don't do this frame anymore, you have to consider other options.

Peter comes back just when our stuff cracks apparently. Was this programmed obsolescence ? 
To avoid any doubt, my rim cracked after many years of hard riding, because my tire was not inflated enough, my total fault 
And a replacement rim is on order.

A BB86 frame has a 41mm diameter hole.
That leaves 41-29 = 12mm for the bearings + a delrin sleeve.
Small balls, tiny rings, etc.
That makes apparently a very weak assembly.

A BSA frame has the bearings outside the frame, allowing more space for the bearings.
So this one is better.

BB386( a wider PF30 ) is for me the best one.
Industrial(cheap) size bearings and light.

However from my experience on my gravel and on my MTB the SRAM BB86 DUB is surprisingly very durable.
And cheap.

...I don't think bleeding and installing hydraulic brakes is worth it personally. I have installed 105 R7020 twice and both times ended up with mineral oil literally everywhere

A couple of bleeding more and I'm sure you'll do it without a drop on the bike or floor.
I'm happy there will be some price competition for hydro brakes.

maybe you think about the 505 because it's your mate for a long time now. Regarding the style and maximum tire width it's  in any case more road bike related than other frames.. but the optic with the low seat stay is not old-fashioned...

I badly notched the seatstays last year (or the previous) by not attaching a mudguard firm enough.
On top of knowing the design is from 2015, how could I not find it old and in the need for a new one ? 
The 696 is too much MTB for me. I can't stand the seat stays/seat tube junction of the 707.
I didn't ask Wing about the 606 availability yet, so I can still dream a little about it...

The 606 looks good too! I was interested in 505 because there is many reviews online.

The 505 design starts to show its age.
I see more the reviews here and on the gravel forum, as a result of Carbonda's frame quality and service, than just this specific model.
If I remember well the 505 was the first of their frame to be presented here.
We should ask Wing about the availability of the 606.