Do you mean you already have an old style file, or would you have to create it on demand?
If you already have one, I'd suggest to just upload it, backwards compatibility is a thing, after all.
However, if you'd have to create it first, then don't do it just for me, of course
!
Personally, I am not going to move on to the new format until it has something added that makes it superior to the old version. Mere game mechanic changes like the deadly ceiling or new graphic sets don't really do that yet, because they're basically just different expressions of what you can already build with the old version (if I want a deadly ceiling in 10.13, I can easily make one out of fire traps or similar). I will consider it once the jumper and/or shimmier have been implemented.