FWIW, personally I am not entirely sure I would completely like the behavior you describe for Omnfocus. For one thing, I am not sure I would always want to have to go to a separate context view to see them, but I could probably live with that. More importantly, I would not want to have my "true/hard" ticklers mixed up with any "soft-tickled/prioritized" items that I might actually want to consider doing even before the date. The "true" ticklers ("definitely premature or impossible" before a certain date) I really would not want to see, but these "soft-tickled" "low priority" items I would want to see clearly in order to be able to consider doing them. (But maybe you could use a tag etc to distinguish soft and hard?)
I definitely agree that tickling things can be useful even if the date is not carved in stone. The example you gave about bulbs sounds very plausible (even though I do not know anything about bulbs). Even if it is not strictly impossible to start now, there may be obvious advantages etc if you wait (for example, context-energy type synergies etc), and the unnecessary delay may not matter much. So I am not trying in any way to sway you out of using that method or claim that it is wrong. But it is not always the best.
Let me give you a silly-simple example of where the soft tickler approach will not work well. Say you have a tarnished door handle. You find it a bit ugly, and although it is no super big deal, you are definitely prepared to pay the few bucks it will cost you to buy a new one. But the only place to buy them is in some very inconvenient place that you do not often go to, and you are not willing to take the time to go all that way just for the handle, so you will do it whenever you have something more important to do there, which could be tomorrow, next month, next year... If you soft-tickle that task for some later date, the location will still be equally inconvenient, and the chances that you will have any other business near that location on your Next list on the date when the tickler shows up are quite slim, so you will usually re-tickle it. The task will tend to never get done unless you make it a habit to scan these low priority Next actions in some more systematic fashion. In the app I am currently using, colored/sortable priorities is the most obvious way (in fact, it was one of the main reasons I changed apps).