One of the things that keep making my workflow unnecessarily hard is that keyframing does not give you access to all of a DVO's parameters. Only selected ones, and whoever decided which ones those are, clearly does not operate the way I do.

The most important ability any keyframe feature should have is that ability to bypass any one DVO with a simple toggle. This makes it possible to drop an effect in and out of a segment on a per-frame basis, which is very useful not only for tricky situations, but also for long stretches where the image content changes dramatically and applying a DVO effect is desirable only in part of the shot. 

The way to do it currently is by putting the effect in its own layer and then using the Router to change the opacity.

Even with the utmost of goodwill, that is a horrible solution that is solving the problem in a backwards kind of way, but even more so, it forces an effect on a layer, because the Router cannot change the opacity of an individual effect in multi-effect layers. 
Imagine you spent endless hours applying effects, only to find out that you have to disable the effect for a period of time. Because Phoenix does not allow you to move an effect out of a layer into a different layer, you will have to redo all of the work.

A simple "Bypass" switch in each DVO that is keyframeable would solve this problem, in an intuitive, easy and user-friendly fashion.