If you're looking to add electrical accessories to your Tiger Explorer, you're going to want to use a fuseblock. And if you're installing a fuseblock, you'll need a source for ignition switched power. Here's one place to find it on the Tiger Explorer without needing to cut into the factory harness.
First, take off the passenger and front seats and the rack assembly on the tail. Note that there are three pieces to the rack assembly: a black plastic piece (with Triumph logo) that insets into the rack, the cast rack itself, and then a thin plastic "tray" immediately below the rack.
Once the rack is removed, you'll find this:
The relay socket circled in green is for the Triumph factory accessory powered top box. This socket has two hot connections. One is unswitched (i.e. always hot even if ignition is off) and the other is ignition switched hot.
Check the always hot connection: (ignition switch is off in this photo)
Check the ignition switched connection, ignition switch off:
Now, with the ignition switch on:
You can use a simple spade connector to connect your fuseblock to the desired circuit (hot or switched).