I keep thinking of a backwards system... where you try to hit a SU early to boost $$$ and then slowly expand your numbers tio cover more of the table, but in order to do so, you would need to increase bet. Without calculating something like...
1u bet 30x SU #1
2u bet 25x SP
4u bet 20x ST
8u bet 15x DS
16x bet 10x EVEN
No idea if my bets cover the previous bets, but thats the example. I realize thats plenty of units per cycle which you are trying to avoid. For me this seems the most promising... trying to hit big early on and if it doesnt work out expand the betting territory & increasing bet size.
So a flat bet of 1u would IMO have to cover the broadest part of the board such as even, then dozen, then doublestreet, then street, etc. I personally havent had luck with that.