Since you have already pissed of Micromeister I doubt that you will get much help.
Otherwise, build a wind tunnel and test in that.
Or, make the guide so sloppy that you would be able to tell if it is stable before it interacts with the guide.
Or, don a hard hat, safety glasses, face shield, hearing protection, steel toe boots, maybe some welding chaps, Lexan shields, head out to the middle of nowhere and build a bunker, disable all video equipment and test what you have. Do not share any information of what you are doing with this forum. Or you could request a special locked thread that will keep out the safety police. Then, you could share with those of us who won't tear you a new one because you are using a rocket motor as a form of propulsion for a sled. (this paragraph was in fun for those who cannot tell if I am being serious or not)
BTW, I like what you have been doing. I find it refreshing to see someone build from stuff they have around the house and make fly.