Yes solusvm will resize the partition when the vps builds to the size of the vps you specify.
The templates in the TDN are general templates that have a mix of filesystems. This means solusvm will only extend the logical volume (HDD) not the partitions of filesystems inside them.
We also have a set of BSD and windows templates in the works that auto resize on build.
So your saying that virtualizor expands the disk, partitions and filesystem inside an active vps? If thats the case then i make sure you take plenty of backups because you will corrupt data at some point.. it's only a matter of time.
You have to understand that keeping data safe always ends in limitations of what you can do. We would never dream of mounting a live virtualized logical volume period.