Get the E-bike out and put it in TURBO!
Otherwise - Comfort = Efficient. Anything that involves puffing and panting also probably involves wasted effort. That's not necessarily bad, that effort may have it's own rewards. Plus of course efficiency isn't always top of my list, I might ride the same hill differently depending on mood, or if it's at the start or end of a ride. I'm also happy to walk, particularly poor surfaced steep sections, it's probably less efficient, though can also be lower intensity. I've sometimes walked and had to wait at the top for those who'd ridden up to get their breath back!
I find climbing on a Rohloff bike different, which can be an issue in a group. Because I know I can always make a clean gear change, I'll change more often. So I might go up two gears and stand to increase speed over a few meters, then sit and drop the gears to maintain it. It's not a big deal, particularly in a familiar group, but finding myself in an unfamiliar one, I'll tend to drop back a bit rather than get boxed into the middle.
But we're all different, I ride with someone who hammers up the steep Peak District hills, which with a couple of exceptions are all short, yet when we went to Wales he struggled on the long steady ones, pretty much the opposite to me.