Unfortunately this does not work for vehicle repair. I don't know if it's possible, but it would certainly be usefull if engineers and vehicle crews repairing would also display a progress bar.
Have you tried watching vehicle health bar yet?
If its full=repaired.
If its not full=not repaired.
Helps me tremendously if I need to quickly check if the repairs are finished or not
I am more surprised why KV-1 and KV-8 are not restricted to 1 as they are both heavy tanks...
For the same reason Panther isn't restricted to 1 as they are exactly the same, or even lower "heavy" category then it as they are inferior in survivability.
The only restricted heavies are the ones who can take and dish punishment, KV series isn't really fit for that.
Long story short: They are heavy exclusively from the name.