Just what I thought when I saw your first post... I have one of these for my Ibanez acoustic bass:
https://www.staggmusic.com/en/products/view/GCAAB.
It sort of just about fits the body, although its *very* tight across the lower bout. The major problem though is that at the headstock end there isn't enough width for the standard PB tuners. The Ibanez tuners are Y key type and are quite a bit smaller. If it weren't for the tuners the Stagg case would do for the odd trip out of the house, but its dreadfully bulky, takes up a lot of room in the music cupboard, about 2.5 standard electric guitar cases, and I don't think I'd be happy about the instrument living in one permanently.
That Thomann case appears to be a lot wider in the tuner area. So there's potential, but you would need to try the instrument in the particular case you have in mind: mail order would seem risky. An acoustic bass gig bag would presumably be more flexible and work a bit better. So yes Simon, another reason to discard the standard tuners... [Simon thinks I should upgrade from budget level hardware, but I'm trying to keep the budget down!]