I can relate to that.

I do not ever use screensavers as I find them both annoying and a complete waste of CPU cycles.
That and the usually poor performing power management apps of any OS I have used.
That said, my main box is not a laptop so YMMV.

In the rare occasion I use my Asus 1000HE on batteries, I just resort to the basic screen blanking.

I'd say that a Devuan live *.iso has many uses, the main one being for new users to try, recovery is really not the best example.
There is many a specialised *.iso for that type of work, usually with a very complete array of rescue tools present.

One of the first ones I came across, knoppix, comes to mind.
I always have one, ready to use, on a 16Gb USB key.

Best,

A.

Remember the 'live' is both for recovery, & new users to try out the distro.....

a) ddrescue  /dev/sda? => some_file? on to another SDD
b) cp some_file? anotherfile?
c) fsck.ext4 anotherfile?
d) mount anotherfile? @mountpoint?
e) cp -n @mountpoint?/* to whatever_place

they need on the new SDD to regain their place in the maintained directory tree
This to restore "as was"/"as is".
The ddrescue took about 4 hours.
currently the cp takes place and then the fsck

This is impeded by the screensaver kicking in and eating cpu time and my time
I changed this now to only blacken the display.
This should be the default on a live system.
Live systems used IMHO mainly for system repairs should not eat electric power, cpu time and admin time for no reason.

If s.o. want to view the screensaver, she can still do.
When doing a repair, there is little time for such games.

Best, if maintainer of live iso changes the default setting for the screen saver