First of all I was surprised it’s even possible. On other hand there are visible “explosions”, a scaling of x axis was quite radical at that frames. Anyway, I uploaded this test, just because it looks at the end quite cool to me 
A few notes:
- square in a corner of domain represents grid size
- domain resized via shape keys keeps grid resolution = change grid size
- shape keys works only with “Adaptive Domain” checked
- animated domain via shape keys affects smoke behavior (velocity?)
- works only in Point Cache format
(OpenVDB format change shape proportionaly, but into initial size.)
Conclusion based on dust trail animation:
- shape keys can help get details by scaling domain down via shape keys
(initially resolution 512 was used for whole trail domain, at the end of animation (were domain is scaled just to camera view), domain use res 512 only for camera view - it’s not a speed up for smoke calculation (I’m not sure about render time), domain use for longest edge of domain always res 512. at the end of trail animation it means even more smoke cells generated in z and y axis)
- even with fluent resize smoke velocity (due grid resize) affects smoke velocity