In 4-player (current Arena) rules, I don't think it is beneficial to avoid lower ELO players even if you could. The difference between placing 1st/2nd as opposed to 3rd/4th seems to matter a lot more than who you might lose to. If you place any lower than 2nd as a very high ELO player, your rating will basically plummet and it can take multiple 1st place finishes just to make those points back up. Against higher skilled / more experienced opponents, the odds of a poor finish are much higher, independent of how randomly friendly the dice and cards were.
I'll play whoever the site matches me up against, but I'm much more nervous against elites.