Having forgotten to remove my giblets cover a couple of times when switching on my Mavic Air at home I found these Mavic Air Warning Stickers which I have received today. Two sets for £2.50 incl P&P and the seem pretty good quality.
Thanks for posting this, I was looking for something like this after a few occasions I almost forgot to remove the cover. I ordered mine and they came today, fast delivery and pleased with the quality.