I think you are asking the wrong question. Its easy to find someone somewhere on the internet that is doing something you'd like to do so you can feel good about it. Its called confirmation bias.
What you need to do is look at the specs of the tow vehicle and trailer and realistically decide where your loading will be relative to those. So, for the 171, max trailer weight is 3252 lbs. You will very likely be near that weight with a fully loaded trailer, especially if you plan to boon dock at all (carrying a full fresh water tank and dual batteries, gear, supplies, etc). If you never plan to camp without water and electrical hookups you can subtract about 300 lbs.
Next, look at your driver's door sticker and find the MCGVWR (the max combined gross vehicle weight rating). That is the most that Subaru allows your total rig to weigh. Take your Suby's curb weight (3884 lbs I think), add the fully loaded trailer weight, and then add a realistic estimated weight of all the passengers and gear (grills, bikes, tents, coolers, folding chairs etc etc) you plan to carry in the vehicle.
Compare those numbers, If you are over the MCGVWR don't do it, you will be overloaded, unsafe, and open yourself to significant liability if you have an accident. If you are under, then its a personal decision about how much safety factor you want. I personally want to be at least 10% under the MCGVWR all the time.
The other spec to check is hitch weight. What is the max hitch weight on the Subaru? To mitigate against sway, the trailer needs to be balanced so at the very minimum you have 10% of trailer weight on the hitch under all load conditions. 11-12% is preferable. So that is pretty much right at 350 lbs for a fully loaded 171. Ignore Forest River's dangerously low published hitch weight.
Check the towing section of you manual to see if Subaru allows you to use a weight distribution hitch. That doesn't give you more hitch capacity but it does significantly improve ride and handling of the rig.