Well, I hoped someone with more recent experience would chime in. It's been 20 years since I used tubulars, but here's what I remember. While the glue is important, the inflation of the tire will hold the tire to the rim. The glue is largely there to prevent the tire rolling when you're cornering hard and to keep the tire on the rim if you get a flat/slow leak.
Back in the Drillium days, racers used to try and use the minimal amount of glue to reduce rolling weight and a tire inspection was part of the starting line ritual.
There are actually two kinds of glues.
One is a sort of shellac that works very similar to contact cement.
The other is more gooey and never really dries. ( Looks like snot comming out of tube).
I always used the second kind since there was a reasonable chance that if you needed to mount your spare tubular on the road, the old glue on the rim would work until you got home. The shellac kind required that both the rim and tire have a relatively recent coat of glue.
That would be my primary concern with the tape. How well it does it work when you need to deal with a flat on the road? Although now that I think about it, I can't remember having more than one or two flats in over 10 years of riding tubulars.
With any luck, my likely incorrect memories will shake some real answers out of the trees.