Welcome to the Forum!
According to the 2005 Hi-Lo sales brochure, the GVWR of your model Hi-Lo is 3840 lbs.
Normally a bit more information is needed... like: What year is your Outback? What is your engine size? However, I went to the Camping Life listings for vehicle towing capacities (
http://www.campinglife.com/towrating/index.cfmhttp://www.campinglife.com/towrating/index.cfm) and for a 2008 Outback with the larger engine, max towing capacity was 3000 lbs.
The Hi-Lo brochure does list your 1705T's UVW at 2500 lbs. However that weight doesn't account for any factory add-ons, your personal gear, cooking equipment, food, full holding tanks, a full fresh water tank, or even the propane tanks. Adding all that weight together and you'll probably be carrying well over 500 lbs., for an actually weight somewhat over 3000 lbs. Still at or over your vehicle's tow limit.
So my caution and advice is to not use the Subaru Outback to tow your 1705T.
Sorry, I'm sure this wasn't the answer you were looking for, but please be safe.
Jim