Well, looks like I had to wing this one on my own.
I needed to head back to the store for some fresh cream for this, so while I was there I discussed my problem with their professional pie maker. She didn't know the full answer, but said that in her experience, that I should temper the process.
Fortunately, I had the process squared away enough in my brain that I was able to break it down to her very simply, and explain that I needed to incorporate the gelatin-sub last, and while it was still warm.
Based on our conversation, here's how I rewrote the directions for myself:
Preheat oven to 325°F.
Place egg whites in KitchenAid mixer bowl with whisk attachment and reserve.
Combine coffee (or coffee liquor) and water in a small pan on stove and reserve.
Whisk 1 egg, milk, 3 tablespoons brown sugar and cocoa in a double-boiler until smooth. Cook over low heat, whisking constantly, until thickened and an instant-read thermometer registers 160°F, 5 to 7 minutes. Do not let the mixture come to a simmer. Remove from the heat. Add chocolate and vanilla, stirring until melted. Set aside to cool to room temperature. Set a timer for 15 minutes. Keep stirring.
Meanwhile, add cream of tartar to egg whites. Beat in KitchenAid mixer on low speed until frothy. Increase speed to high and beat until soft peaks form. Gradually add the remaining 5 tablespoons brown sugar, beating until the meringue is *smooth and glossy*.
Add gelatin to coffee-water mixture and boil gently. When 15 minute timer goes off, add a small amount of chocolate mixture to the gelatin mixture. When incorporated, add rest of gelatin mix back into chocolate mixture.
Whisk one-fourth of the meringue into the chocolate mixture until smooth. Scrape chocolate mixture into the remaining meringue and use a whisk to incorporate it with a folding motion.
Spoon into the crust and chill, uncovered, until set, about 3 hours.
Oh my, I had to tell my partner and roommates to steer clear of the kitchen for the twenty minutes or so that I needed to attempt this - but I did it! I was making the meringue at the SAME time I was making the chocolate mix at the SAME time I was putting together the gelatin-sub-mixture. Kinda fun, really. ;) Esp. because I was finishing it with less than 2 hrs to be picked up, so I just kept it outside on our back deck to nearly freeze for the last hour it was supposed to be in the fridge.
It set, it wasn't runny or anything, and it looked like a French Silk Pie. I only had two problems - both which were my fault, but learning experiences for sure.
One, I didn't realize I was supposed to butter the pan for the crust.
Two, I didn't realize how much the coffee liquor flavor would take over the whole thing. So I called it a Mocha Silk.
It was DELICIOUS, but not for everyone's palate. And since the crust wouldn't come out, I just served it with the gluten-free homemade chocolate wafers that I fortunately thought to bring with.
Next time, I'm going to try this much simpler recipe I found later: Amanda’s French Silk Pie « Cookie Madness
I also think I might consider just making this into parfaits too - layering the wafers, whipped cream, french silk filling, repeat, chocolate shavings and berries on top. I think that would have been a whole lot easier to make.
I'd love to hear others advice on how they make French Silk too. Hope this helps someone!