The way you're imagining things, the higher docked processor speeds would be almost totally useless. Unless they just made the undocked mode perform so poorly that all of a sudden enabling over double the GPU speed took care of a massive bottleneck.
Has there been talk from Nintendo of the differences people claim there are/or could be when docked and portable? Or is it nothing more than a difference in resolution?
I've watched a lot of youtube videos on people's impressions, and read lot's of opinions and feedback online, and not once have I come across anything that hints towards different graphical settings, or performance differences between docked and portable modes.
Yes some people have commented that certain games might look easier on the eye while portable, but those comments have been because the jaggies aren't as visible.
I appreciate I'm going round in circles with people as we've all got our own opinions on it. Time will tell obviously, but I'm still sticking with my opinion that we're not going to see a scenario akin to say PS4 and PS4 pro where we have differences in performance when docked and undocked and developers having "docked only graphical features".
I believe that any difference in clockspeed when in portable mode is purely to promote better battery life, less heat, and obviously because the device doesn't need to be clocked as high due to only running the game at 720p. I certainly don't believe the notion that because the SoC is running at a higher clockspeed while docked that developers are going to make games run with higher graphical fidelity and higher framerates.
I'll take Breath of the Wild as an example again, it apparently has a native framebuffer of 900p, that is what it is. Then you either play it docked and the Switch will output at 1080p, or portable and it'll output at 720p. I see no evidence whatsoever that there are higher levels of AA, or anything else while docked.
But there are plenty of knowledgeable people on this forum, so I'm sure someone will educate me and provide evidence to the contrary.