Is it possible to buy/DIY a chainguard for a triple chainring with >50T? Most of the aftermarket guards like the Chainboard by SKS only go up to 48T. Is there a reason for this? The bikes I'm looking at buying are 52T or 53T. I'm hoping to stop my right pant leg from catching.

Please do not reply with "roll up pant leg and cover with sock" or "use velcro strap", I have done both. The purpose of my post is to find a solution that doesn't require the preparation of the previous two methods every time I want to ride.