Hi,
Sorry, this would not work. VisualGDB activation system is designed to be a non-intrusive as possible and to avoid frequent reactivations, so reverting to trial won’t deactivate VisualGDB (the feature is intended for checking out the features of higher editions when considering an upgrade).
Please note that we do offer an experimental floating license (that counts simultaneous sessions, but requires continuous Internet connection) in some cases. Please contact our sales with a description of your setup so that we could help you find a suitable licensing model.