I'm glad the gorilla glue worked for you. Those are the best endings!
I almost tried it. And, if I had a smaller area to do, I probably would have, just as you did. But, in my case it was ~1/3 or so of my lower foredeck surface area. I didn't want to end up doing it a 4th time (PO, yard, me, me redo). I was concerned that, doing so many holes, I wouldn't get good injections into all of them and wouldn't have the guarantee of enough expansion and pressure to help
What you saw seems like more foaming than I am accustomed to seeing with gorilla glue with dry wood. I suspect you had a good bit of moisture in there. In that type of polyurethane, water is a big part of what causes the foaming, building the pressure that drives it like that. If it had been drier, I think you'd have seen more modest expansion and movement (there is always some). But the good thing is, unlike epoxy, it can chemically incorporate the moisture into the adhesive.
I tried to dry mine out in advance, but there is no telling how well I did. Spot checking doesn't check everywhere.
The injectadeck will, by design, foam to spec without needing added moisture. But, it can also foam more with moisture, although density can go down as a result (as is necessarily the case when the same mass of adhesive is distributed into a greater volume of space).
I'm sorry you had a bad experience with the injectadeck guy. The first time I called I had the same thing. The next time I called.a few weeks later, he was like a different person. I figured I caught him the 1st time during his day job or family time pr on a bad day and the 2nd time at a better time. He probably spent 30 minutes on the phone with me and also referred me to some folks locally who didn't he injection. They were great with that part -- but lousy painters. At any rate, sorry he wasn't in his better mood for you!