I had good experiences with the Ground Effect Tardis the 2 times I've used it and when packed up it's about the size of a large phone book so it's inexpensive to post to your destination or no trouble to leave it with someone.
https://www.groundeffect.co.nz/produ...mpact-bike-bag
I'd certainly trust the Tardis with a steel or aluminium bike, but for carbon fiber something like the Post Carry Transfer Case is probably better.
https://postcarry.co/products/transfer-case
I've used both bags without incident.
I recall very well you talking about your TARDIS bag years ago ( grew up watching Dr Who, so always remembered the name) . It's been years since I've looked up prices, but for now, I'm pretty sure I'd like to stick to boxes ( goofily I still have the box I used last summer, in my garage)
But I appreciate your comments and experience.