Doubt that would ever work, who would you buy such a ticket from for example? Cash would need to be divided up between all clubs participating in such a venture, and they would all need to play ball for it to work.
I can see the point of the idea when the objective is to get folk into an otherwise empty stadium...there are difficulties when you include clubs like Hearts, Aberdeen and the uglies who tend to bring more support than others, and also are more likely to sell out the home end with the option to acutely cut the away allocation. For any club the option of putting home fans first needs to be there, which means guarantees about away allocations in advance of the season might be undesirable.
The only ones who can help mobilise the away support of smaller clubs are the clubs themselves, for bigger clubs like Hearts the loyalty points system works well since demand tends to be good for away games, for SMFC it wouldn't work so well since the question is not who gets the away tickets, but who wants them, and what can we do to make you go