I think it would probably work. Since you're adding weight every week, and only testing once a month you will slowly work away from the 70% range, and then come back down once you retest. This kind of waving should allow for long, consistent progress. For instance, if someone's 1RM was 150 they would start at 105 (70%), add 5lbs per week, and end up at 120lbs (80%) on the fourth week.
Alternatively, you could try something like the singles pogram Pavel posted in "<a title="Kettlebells and Deadlifts go Together Like Pickles and Vodka" href="http://www.strongfirst.com/kettlebells-and-deadlifts-go-together-like-vodka-and-pickles/">Kettlebells and Deadlifts go Together Like Pickles and Vodka</a>". So, instead of increasing the volume through the week you increase the weight and decrease the volume. The hypothetical lifter with a 1RM of 150 would go from about 100lbs for 15 singles, to a top weight of 130 for 6 singles, before adding 5lbs the next week.