Safe to install an after market tailgate ladder?

I have a back injury that makes climbing in and out of the bed of my Tundra a little challenging. I've been considering the Harbor Freight tailgate ladder which has solid reviews. The only thing giving me pause it requires drilling sheet metal screws through the inside metal of the tailgate when mounting. Would you be concerned of future rusting or damage? I think I'll use silicone to fill around the screws if I decide to do it.

 

Personally I have no issue drilling holes. Open up the tailgate panels and clean up the hole on the inside
after you are done. Silicone is not the right thing. Paint, I'd use spray bomb rust paint of your choice.
Tremclad etc. I would also make a backing plate identical dimensions to the piece that bolts down on top
to have inside to clamp it securely onto the tailgate sheet metal to prevent warping and distortion, cause
it's going to carry your weight and whatever you are carrying.

 

I was considering installing one also after reading through this thread..
https://www.tundras.com/threads/tailgate-ladder.153288/

It's a different ladder but seems a bit better then the HF one. This one swivels giving you different angles of access. Not sure if HF does that.