What is the safest way to leave my MacBook on 24/7 with macOS Mojave?

I used to use sudo pmset -a hibernatemode 25 to try setting my MacBook to hibernate instead of sleep, so that it pulls power away from the RAM/hard drives, etc. and puts the laptop into a proper sleep. A few major updates ago (maybe El Capitan), pmset ... 25 no longer worked to set my MacBook into hibernate/safe sleep. I'm using a MacBook 13" from 2017. Is hibernate no longer supported on this model?

After hearing about the defect in the 15-inch MacBooks from 2017, I have to admit that I'm concerned they'll find an issue with 13-inch MacBooks as well, and I want to be as safe as possible.

I use a lot of applications whose state needs to be maintained across many days for development and testing, so shutting down my computer every day is not efficient nor is it a viable option.

Here is my pmset -g custom after running sudo pmset -a hibernatemode 25 to try enabling hibernate mode again:

pmset -g custom

Battery Power:
 lidwake              1
 autopoweroff         1
 standbydelayhigh     86400
 autopoweroffdelay    28800
 proximitywake        0
 standby              1
 standbydelaylow      10800
 ttyskeepawake        1
 highstandbythreshold 50
 powernap             0
 gpuswitch            2
 hibernatefile        /var/vm/sleepimage
 hibernatemode        25
 displaysleep         5
 sleep                180
 tcpkeepalive         1
 halfdim              1
 acwake               0
 lessbright           1
 disksleep            10
AC Power:
 lidwake              1
 autopoweroff         1
 standbydelayhigh     86400
 autopoweroffdelay    28800
 proximitywake        1
 standby              1
 standbydelaylow      10800
 ttyskeepawake        1
 hibernatemode        25
 powernap             1
 gpuswitch            2
 hibernatefile        /var/vm/sleepimage
 highstandbythreshold 50
 womp                 1
 displaysleep         10
 networkoversleep     0
 sleep                10
 tcpkeepalive         1
 halfdim              1
 acwake               0
 disksleep            10

pmset -g cap

Capabilities for AC Power:
 displaysleep
 disksleep
 sleep
 womp
 acwake
 lidwake
 halfdim
 gpuswitch
 standby
 standbydelayhigh
 standbydelaylow
 highstandbythreshold
 powernap
 ttyskeepawake
 hibernatemode
 hibernatefile
 autopoweroff
 tcpkeepalive
 autopoweroffdelay
 proximitywake

I'd say "Nothing". Assuming there is an defective battery, you can't 'manage' its safety with any specific behaviour. It could fail and overheat while in use, or while charging.

The odd recall notwithstanding, Apple has worked very hard at making laptops use minimal power when closed, while also allowing some necessary background tasks; and then letting them spring back to life when you open the lid.

Modern SSDs use a fraction of the power of the old mechanical hard drives that needed to be spun down to save energy.

I rarely turn off my 2014 MacBook Pro, and only reboot it when updating the OS or troubleshooting.

Your setting of hybernate mode is the one to achieve exactly what you described.

But you are correct. I use this setting since many years and through many versions of MacOS (Yosemite, El Capitan, Sierra & High Sierra). From memory I reported many times the same problem to Apple about this mode failing on output of hibernation when the battery was nearly empty.

I guess there is a problem about correctly evaluating the power required to make the /var/vm/sleepimage dump of the virtual memory. Since they never answered me, I guess they never fully understood the problem.

Now I know for sure that the function lidwake is failing.

Is hibernate no longer supported on this model?

No it is.

But since a negative question is leading to confusing answers here is a clearer one.

The command to check directly the availability of this function is:

pmset -g cap

and look for the key function: hybernatemode