My place on your scale is probably around a two, I think, and my dreams are always vivid.

The vast majority of my transitions, though, have been with DEILD. In my experience, and opinion, visualization is not necessary with DEILD; in fact, given that the transition happens so quickly (often in as little as a few seconds), there really is not time to do any visualization: the dream from which you are waking should have provided enough imagery for you to hold onto as your body goes back to sleep. On top of that, visualization might actually inhibit your DEILD attempt, since doing so might damage your link with the dream from which you're waking. I may be running counter to the internet manuals (which happens a lot with me), but I see no reason to do visualization during a DEILD... so DEILD might be just the thing for aphantasics.

Also, classic WILD's can work just fine without visualization... since WILD is essentially about maintaining waking-life self-awareness as your body falls asleep, and there is no visualization involved in that, doing a WILD without visualization is certainly possible, and not even more difficult. Though visualization is a handy tool for forming dreams, it is not vital to successful WILD's, or even necessary, really.

Given that MILD does have a visualization component, I can see that aphantasics might have some trouble there. I have found though, that intellectual visualization (focusing on the idea of an image rather than conjuring an actual image) can inspire the prospective memory necessary to recognize and act on dream signs.

Finally, my dream recall has always been pretty good. That might be because, rather than attempting to retain images, I tend to remember the dream as a story, and not as a series of images.... this could be because my waking-life trade is writing, I suppose. So, again, intellectual visualization seems to work for recall as well.

As usual, I'm running a bit contrary to the general consensus but, since I'm a lousy visualizer who has had some success with LD transitions, I figured my thoughts worth sharing.