Yes this is possible to do both mssql copy only backups (they mssql backups MUST be copy only) and snapshots but there are some limitations with doing this
1) you must not overlap mssql copy_only backups with a snap manager task as this will cause snapmanager to wait and will attempt to load the snaps into memory (i presume its loading the snaps into memory as process uses as much memory as it can)
2) if you do not take copy_only backups this will cause the LSN chain issues with the databases concerned
3) if you have multiple mssql instances you can only run one instance of snapdrive at anyone time (a limitation of the snapmanager product) so scheduling is difficult
4) taking snapshots from snap manager for sql scheduled jobs works just fine until a database is added to mssql server and snapmanager cannot add it to the job so you MUST script out the backups and run them from sql server or delete the job and re schedule the snap job.the issue here is that if the snaps fail the mssql job is successful but the snapshot is not in a consistant state but mssql reports successful job .
(i hate running .exes from mssql but there is little option)
Please let me know if you need further details