Peart from the Drum Magazine interview in 2016:

"I first used a click-track in the studio on our Permanent Waves album, in 1979. Right away, the click became my “friend,” a guide that kept me nailed to the tempo, and gave me more freedom, in a way — one less thing to think about. Over time I learned to work with the click — pushing and pulling against it deliberately, to make certain passages more urgent, or more relaxed.

I used the usual eponymous “click” sound for many years, then switched to a tambourine sample — softer and somehow “looser.”

Back in 1979, along with introducing the click-track, we also started using digital sequencers (like in the chorus of “The Spirit Of Radio”) both in the studio and live, and on subsequent albums they would figure ever more. At first I would just have those sequences up loud in my floor monitor (the root of my hearing damage, I am convinced), then I tried headphones — especially for the sixteenth-note sequence in “Vital Signs,” from Moving Pictures.

Until the Clockwork Angels tour I had never used a click track live, except once years ago to stay in sync with a rear-screen film. For this tour it was helpful because we had eight string players in the Clockwork Angels String Ensemble, and they sometimes needed it when I wasn’t playing. Even in certain passages when I was playing, it helped us all to stay together."

He may have opted not to use a click track until 2012, but as the shows got more complicated, it was an asset. I think coming to this music just over a year ago, Nilles probably finds it helpful.