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sudo history is a bit older than linux not to mention ubuntu. sudo development is/was maintained by OBSD (although OBSD uses mainly doas rather than sudo nowdays) however system is as secure as one make it.
I don't see any memory gains. I would not expect RAM use changes because all services are the same so with old or new init RAM usage is the same, that is 296MB with LXDE running.
Boot time speed is also similar ~6-7sec.
Anyway second day running an no problems with X or any other services. Still I will run OpenRC vesion alongside sysv for some time before deciding to remove one or another.
edit:
After removing few services usage went down to 253MB. Still this is not related to init but what I run. CRUX with fluxbox runs at ~80MB so if needed RAM usage can be trimmed but I don't see any need for this as I assigned 13GB RAM for Devuan which is more that this VM would ever need as far as I know.
thank you. easy installation on devuan ascii 64-bit with zen-4.13.5