Please add a vote for me as well.
I work in a lab and there are certain tasks that produce material which has to be used for the next task within a given number of days (or hours, in some cases). The consumption task definitely depends on the production task (finish to start, no lead time), but I also need the production task to depend on the consumption task (start to finish, or start to start, with negative lead time). In the current version, this leads to a violation (dependency loop), even though there is nothing logically incorrect.
Similar in concept, there are "waiting" tasks (no staff assigned) that take a certain duration, but cannot be left forever. This is like the classic "allow paint to dry" task in the tutorial, but with the added constraint that the freshly painted surface should not be exposed to the air for too long before applying the next layer of lacquer, lest it attract dust.
I really look forward to support for this kind of scheduling, and am also interested in more workaround ideas.
I'm currently demoing OmniPlan, and would have had no reservations about getting a license had these features be present. Now it's going to depend on what workarounds I can put into place.