The alternator will hate that draw, at low speeds you will be discharging your battery.
30 years ago, thats right, 3 decades ago cruisers and touring bikes became different animals. Touring bikes have the seats, the shields, the electrics, drive shafts, cooling systems etc. Test drive a Gold Wing then jump back on your Triumph and make an honest statement about what you would rather sit on for 10 hours.
You can tour with the TBA but if that is mostly what you want to do, IMHO you bought the wrong bike. The TBA and SM were meant to be boulevard cruisers not touring bikes.
Before anybody takes offense, you certainly can tour on it! You can spend several thousand and make it a touring bike that almost has what other touring bikes have standard.