I wouldn't dream of trusting a bag of sand on some decking Daz. Wet they can be like ice rinks.
Holes in decking? Customers are going to have to take that one on the chin. Most decking is covered liberally with holes anyway, it's where it's screwed to the joists underneath.
For a one man band setup this is a great solution. Solid, safe. I'd fa r rather trust my safety to something secured than just an objects weight.