Consider other variables: observation, approach, presentation, and tippet length.
An observant angler fishing the LLH (or anywhere the trout are visible) can deduce what the fish are feeding on, at least with some degree of accuracy. That is an advantage of sight fishing so use it when you can.
Wear subdued colors or camo. Every time I go there I see guys standing right over top of the fish they are trying to catch. :-? I noticed the trout in the LLH Heritage section to not stop feeding when someone approached, but they do get more selective.
Present the fly drag free. If that doesn't work try twitching it to get a response. Each trout may prefer a different fly and/or presentation. Be flexible. In the past, I've caught some nice rainbows by twitching sucker spawn UPSTREAM! :-o
The tippet length should be 3 feet plus. This is to prevent drag and allow for more natural movement. On general longer tippet is softer.
This stuff is all second nature to most of us, but inexperienced anglers must think of these things constantly until they become ingrained. It doesn't hurt to review them periodically.