Yes, they're ugly, because the usual customer is commercial. However, I've been working with a guy who gets Decora controls, so there's no ugliness problem.

70 volt and stereo are different worlds. You don't find stereo 70 volt controls because 70 volt stereo is a silly idea.

"Stereo" means "solid" and the idea is that you have TWO speakers that, because of their fidelity, positioning, and the acoustics of the room, give you a hard image of where the different players are from the ONE SPOT in the room that's perfect. The sweet spot.

On the other hand, if you need to fill a space with music and hear all the music everywhere, you mix the two channels of stereo to mono before they go to the amp. All speakers then have all the audio.

And with a 70 volt system, the quantity of speakers is solely dependent on the power of the amp and the powers at which you tap the transformers. If you try multiple 8 ohm speakers, you have to series and parallel speakers to get them to present an 8 ohm load to the amp; this means your speakers are always multiples of 4. With 70 volts, if you have 13 speakers you can easily add two more for a total of 15 with zero problems... if you have planned the transformer tap levels correctly.