A much better option for 1010 rail is this bike stand from Amazon. It has a much wider footprint so it's very tip resistant, the jaw is square so it forms around the rail perfectly and it adjusts multiple different directions so you can aim the rail just how you want. It's also taller so easier to attach starter leads
https://a.co/d/5JnIToD
Edit: currently shows unavailable but might become available again in the future.
Not to blow my own horn too much, but an inexpensive rail pad design that is much more robust than a Mantis is in the May/June 2022 issue of Sport Rocketry.
Rail angle adjustment via adjustable length legs (two of them).