Lawnchair VS TapTap

I would like to use Lawnchair on my Hi Reader Pro, but whenever I set it to use a third party launcher (obviously I haven't tried them all, but I tried 5 or 6 with the same outcome) the "Recent Apps" (Square Button) stops working after a few uses. By that I mean: nothing happens when it's clicked.

You can download it here: https://github.com/LawnchairLauncher/lawnchair

Could you please install Lawnchair Launcher & check if the notification is visible in the long press menu?

Launcher

And probably the most latest version (but not final release). https://github.com/LawnchairLauncher/lawnchair/releases/tag/v12.1.0-alpha.4

Lawnchair

Tap, Tap (version 1610): double tap on back of device

This app has double tap with sensitivity adjustment, works perfectly for me with no noticeable battery drain. https://github.com/KieronQuinn/TapTap

Just a quick shout-out of an app I discovered, it's a backport of quick tap for older android versions, but also has sensitivity adjustments and works great for me. Always triggers when I double tap (unlike the originl) and I've never had it accidentally trigger. https://github.com/KieronQuinn/TapTap

That said, some apps do use Material Design 3: Sync, Simple File Manager, Auxio Tap, Tap

Github

Tap Tap provides customizable tap routines

Tap, Tap (version 1600): double tap on back of device

there also is an app named "tap tap" available on GibHub with direct integration as Tasker Plugin.

Have a look at Tap, Tap.