Mast steps add weight to the mast and tend to snag halyards.
I have tested different solutions for climbing or help the person at the winch hoisting me.
This movable step is made of a piece of plywood, one cleat and two eye straps.
You need a free halyard to put the step on.
I use it with a good bosuns chair like this - I strap securely into this.
When going up the mast with a helper on deck the procedure is like this.
1) I stand on the step.
2) Helper take the slack on the halyard's (use two for safety)
3) Lift the step using my foot
4) Stand up in the step
Repeat 2-4 until at the top
Doing work at the top can get awkward hanging in a bosuns chair.
If I need to get higher up I can stand on the step.
Going down i bring the step with me as my helper lower me down.
I have found that this step is more stable than foot loops.
This step can be used in combination with ascenders if you like to climb solo.