Could the Space Shuttles other than Enterprise easily do drop tests from the Shuttle Carrier Aircraft?

This question was inspired by comments on this answer.

The Space Shuttle prototype Enterprise was only used for approach and landing tests, for which it was flown on a carrier 747, until it was released, and would then glide like a normal post-reentry Space Shuttle.

• Would the regular Space Shuttles have been able to do these drop tests?
• How much would have needed to be tinkered?

The launch/startup sequence must have been quite different for example.

Related:

• How was Enterprise held/released from the carrier 747 for the Shuttle approach and landing tests?