That sounds like a good schedule of introduction. We very slowly increased the amount of time they were together and they seem to have worked it out mostly to their own satisfaction, despite the caterwauling. We just started putting them downstairs together in what we refer to the "Kitty Palace" (a more-or-less kitty-proofed room with lots of windows looking out over bird feeders) and they seem to do pretty well without a lot of supervision. Mostly they pick separate spots to nap or watch birds and there's very little tackling and pinning.
So they've come pretty far, and we have the time (we're both retired and home most of the time), so we'll take it as slow as we need to. I still can't envision them spending the night together, though. JD seems to enjoy his alone time at night too much, and Dusty is content to sleep upstairs in her comfy bed. And I still have never seen them cuddling together, which would go a long way to setting my heart at ease about their relationship...
Our next goal: getting puppy Lili grown up enough that we can have dogs and cats all free in the same room together...