I really haven’t tried to “hoodwink” the system since I just attach an external disk. If you don’t want it connected - the system runs well and reminds you every 2 weeks or so to connect the external drive.
You can make use of the GUI and local snapshots features once you get one backup to an external drive, even when it’s not connected.
If you really must have snapshots without the Time Machine setup automating all the steps and triggering the automatic snaps, you would have to create and manage the snapshots with another tool or command line snapshots.
Apple only documents this as a function call fs_snapshot_create which has a very excellent manual page
man fs_snapshot_create
Once you’ve created snapshots, you can list and delete them easily with the diskutil command line tool. Disk Utility can also show you snapshots so you can visualize, mount and delete them.
