This amazes me what I read sometimes. Let's think about this for a second. The OEM cap has a vented ****** that is about 2" tall. There is a splash shield on the interior. Adding the power steering vent tube extends this ****** to about 4", has an arch that runs along the side of the reservoir to stop the cap from turning. It is that simple.
So I read to not use this because it adds risk to vent fluid along side the reservoir and supposedly onto waiting tires. Keep in mind that the fluid now with the tube would need to go 4" up, around the arch and along side the reservoir. The advice is to keep fresh fluid (true), tighten regularly and leave OEM cap alone. So this advice is to let the fluid instead spray out the 2" ****** all over the reservoir and along side apparently onto your tires. Give me a break.
I said this before. Change fluid regularly. Duct tape, strap, whatever the cap. Do not kink with a hose and block the vent. Use the tube if you want it to look good like the rest of your engine. It is logically impossible to ADD risk by using the tube when fluid would only have to go further up 4" versus 2" to get out. Tube or not, the fluid (if it ever made it out) would exit the same location.
The confirmed fires are only if a cap came off and landed on the headers and melted. Stop worrying about the fluid and keep the cap on.