R & G sell a prop stand enlarger for under £36: I don't know the cost of the SW Motech version.
As an alternative to a flat can, plastic prop stand supports are available on eBay for less than £4 and could be carried in a jacket pocket, but as I have had tank bags on various bikes for years ( anyone who owned British bikes always carried a bag for tools spares etc) it has not been a problem to carry it there. Old metal drinks coasters/ redundant ashtrays serve the same function and have no sharp edges
I quite like the fact it's always there on the stand foot. Just kick the stand down and you're laughing. Bit easier than messing with the other options which I have used aplenty in the past. Though budget-wise it shouldn't really be at the top of anyone's list of 'essentials'.