@Veritybelle may have the bolittle

(I may be thinking of another bag she has, not sure. If so, my apologies for the tag). Both are roughly the same dimension, but the Bolittle has crossbody capability. From pics that I’ve seen, I think the KD 25 may hold its structure better.
I’ve only seen the KD 25 IRL at a glance (I was offered a limited edition KD 25 in Milan a few years ago and passed. I wasn’t sure that the wristlet was right for me, but other members have an Etsy hack that allows for a shoulder strap conversion.
My personal preference would be the bolittle, but IMO it’s a more casual bag.
ETA: have you thought about the sac a depeches 21. Less long and more square. It’s crossbody and adjustable and has an outside pocket. I think it’s more dressy than the belittle and less than the KD 25.