I had the same issue. Did a bunch of troubleshooting with Apple over the phone and in store. The final diagnosis was a logic board and wireless card replacement.
When they took it in to repair it, the tech noticed only one of the three antennas were connected to the motherboard. His theory is that the one antenna was enough to support a connection or two but became overloaded in certain situations, very easily. After reconnecting them all has been working well.
So my suggestion to you is to either open it up yourself or bring it to Apple and see if that may be the issue.
Edit: to answer your actual question, you can't do it from anywhere except Recovery Mode, so anything you do must be done from there.
Tested on a similar 4,1 upgraded to 5,1 [but I have a flashed graphics card so I could see what I was doing]
Reboot & at the chimes hold Cmd ⌘ R for about 10s.
Wait until you get to Recovery Mode, which for me took approx 45s from the chimes [I'm on SSD but I think it may have chosen a Recovery on another HD to actually boot from] Give it a minute or so just to be safe.
Fn Ctrl ⌃ F2 will switch focus to the menu bar, specifically the Apple logo, top left.
It appears that whatever you have set in System Prefs > Keyboard for "Use all F1, F2 keys as standard function keys" that this option is disabled in Recovery, so even though just Ctrl ⌃ F2 works for me in a running OS, in Recovery I needed the added Fn key.
From there, you can navigate using the arrow keys
Pic from https://apple.stackexchange.com/a/254167/85275
From that you can see that Terminal is 4 to the right, then 4 down.
It's 4 not 3 because the first down arrow opens the menu.
Hit Enter & Terminal will launch.
Type csrutil disable
& hit Enter
Type reboot
& hit Enter.
If it reboots, you got it right - otherwise you'll have to have another guess.
BTW, golden rule, as you have discovered, is keep your crappy old stock Apple card somewhere safe, for occasions such as this ;-)
Additional note: Fn Ctrl ⌃ F2 is a toggle. First will select the menu bar, second will deselect, so make sure to only do it once.
Best Answer
Powerbeats3 do not have active noise cancellation.
They only have passive noise cancellation and there's been no published plans to add ANC to them in the future.
There's nothing for you to enable/disable for these headphones.