I've been using dual boot of #ubuntu and #gentoolinux for a year in my #slimbook . (Sharing firefox and thunderbird profiles, nextcloud and zotero between installations)
I hadn't used gentoo since I was twenty and I was afraid
And now I have just removed ubuntu! Full time gentoo now

its an openrc startup, so #gentoolinux or another distro packaging openrc and no systemd 😉