If mandates say plan is immediately passed, does it fiat past all real world constraints? Rider, agenda crowd-out, most politics would all be ignored. I'd argue that most fiat-linked DA's happen during the process of fiat, and that the real world outweighs. Problem with that is that fiat is theoretically instantaneous, there's no brightline between fiat-linked DA's and solvency abuse, and that all non-postfiat arguments are questions of would, not should.
Generally the standard I've seen is that it avoids "process-based disads" but can still link to the "political consequences". So you don't push something off the agenda, but you might have to suffer with backlash from your base.
If process-based arguments can link, then every neg can just re-introduce the "would they?" question by saying, "opponents will filibuster". The question is, again, "Should plan happen" not "would it?" Unless your plan includes riders (and hence probably extra-topical planks), the neg doesn't get to argue that "plan is so important X rider will get attached to it and pass." Theoretically they could argue that because one side made a concession in this case, they expect a concession in another. The "concession" argument is, in my view, one of the most borderline disads: did they really "make" a concession, or are we just imagining a world in which plan happens?