Depends what your mean by reliable but there is no guarantee your bid will be successful. All that can be said is chances of success increase if you bid a smaller amount.
After two rounds of bonds my initial thought is the bidding system brings with it too much faff. You have to think about what to bid each month, commit funds for a few days before the bonds can even be issued (with no interest earned in that period), and there is no guarantee of success. If not successful you then have to spend time finding somewhere else for that money. I don’t think this faffiness is conducive to good saving/investing habits.
I’d prefer if Dozen’s met their goal of helping smaller savers/investors by capping the bid amount to a level that is likely to be successful. Or perhaps offer some predictions on likelehood of success of different bid amounts. This won’t guarantee success but Dozens should have a lot more data to base effective caps or likelehood scores on than individual savers.
If they capped maximum bid amount I think a better tie breaker (in the event of running out of bonds in any given month) would be to give preference to to those who use Dozens’ others features. E.g. those who regularly do their spending through Dozens. This wouldn’t help me as I don’t yet use other aspects of Dozens but it would feel to me to be more reasonable to give preference to Dozens primary users.