First and foremost, there isn't a awning or RV manufacturer out there that I know of that says tying down an awning is a good thing and your accepting any and all risks of damage to your awning by doing so.
With that said, I among others do it regularly when at a site for extended stays.
May I suggest that if your going to tie it down, also add support poles to support the underside of the roller tube as well.
This way, the roller has absolutely NO where to go up or down and also when setup correctly, removes the tension on the awning arms where they are attached to the RV.
There are a number of ways to do it. The simplest and cheapest way I have seen is to fashion homemade ones out of PVC pipe with a large T on the top and then cutout the top of the T out a bit in a fashion so that the roller tube will lie in the rounded cutout.
I found some adjustable tree branch supports that already have a curved holder on top that fits the roller tube almost perfectly. I then slid them into a longer piece of stronger PVC pipe to make them even longer. Then I just use simple ratchet tie downs with dog stakes, taking care to just "snug" it down into the supports. Others may chime in as to what they do.
https://www.groworganic.com/propacro...h-support.html