You should absolutely not leave out your VS experiences from an application - it is an impressive form of work experience that will only strengthen your apps. Like Jaysen said, it is common amongst applicants to have not moved on from a VS to a TC (not all law firms have the intake to do so + it remains highly competitive) firms are aware of this.
Agreed. The other important part of securing a vacation scheme is that it's pretty clear proof of your commitment to commercial law. Securing a vacation scheme means you have dedicated significant time to apply, interview and intern at a commercial law firm.