Yeah it might be better with a person to swing and a qualified person in the rear cockpit but not alway practical. No idea how many times I have swung a Tiger prop solo but IMO its safe 'enough' provided you know the aircraft and what you're doing. If a Tiger Moth needs more than throttle CLOSED to start its set up wrong. The mag switches are on the outside so you can see them (and reach them quickly if necessary).
If there is no one handy who KNOWS WHAT THEY ARE DOING you are better off doing it alone.