I would request every foil kiter not to use any kind of anchor for launch and landing. NEVER, also had some bad experience 15 years ago.
The only exception is landing on the safety and fixing the safety for a short moment on an object to get to the kite, if you are alone and no other possibility.
All other usage of anchors or boards as an anchor in the lines especially for launch is extremely dangerous for you and everybody downwind! Please don't do this.
It is possible to launch a foil kite also in strong wind conditions alone with some sand or a bag or board on the 1-2 m folded upwind tip, without help, fully inflated at the corner of the wind window with very low risk.
You just have to take your time and learn this in low wind and then always stronger. You can find many explanations and videos in the web and the instructions.
When doing this maneuver there shouldn't be any uncontrolled moment, just take your time, go one step back, inflate the downwind tip, let the downwind tip stand up and stabilize it in the wind, one more step back, inflate even more, get the feeling for your best position in the wind window. And on the end when the kite is completely inflated and standing on its tip still fixed by a weight on the ground. You will just need a final little pull to free it from the weight and then can fly the kite upwards.
No uncontrolled situation and especially no uncontrolled flying anchors around.