Transferring plants from one frog viv to another has its risks. You have to decide for yourself whether you can tolerate the risk of spreading some pathogen between vivs. Apparently healthy frogs can still harbor nasty pathogens.
You can try to "cleanse" plants prior to using in a new setup. But no method is 100%. Better safe than sorry is my motto though at times it has meant not using that perfect plant in a 2nd viv.