I’ve travelled with a guitar on both EasyJet and ElAl. No charge but size limited and a bass would be too big. I have a 12fret parlour guitar which is just right. Saw a guy trying to get on with a bass in a soft case once. How he got past the ground staff I have no idea, but the cabin crew would not let it on and were offering to put in the hold!!!!
I should think devising that design was pretty difficult too. I don’t want to be rude and each to his own, but that’s probably the ugliest bass I’ve ever seen.
I think it’s interesting that despite the world and it’s sound engineer going on about the P having the pickup in the perfect sweet spot, the world’s most recorded bass has the pickup moved forward closer to the neck.