in this thread (https://support.hifiberry.com/hc/en-us/community/posts/360009628238-Functions-Wireless-Remote-Control?page=1#community_comment_360003123197 ) the topic of safely power a HifiBerry system has been discussed.
I have a similar issue and thought about another solution. For me the question came up if it is possible to connect to RPi and HifiBerry HAT a second HAT, an Uninterruptible Power Supply (UPS)?
If power is cut from the RPi the UPS will detect this and power the RPI for some time. If the power does not come back within this time frame the UPS gives the RPi via GPIO pins a shutdown command.
Basically this is the behaviour of an like this UPS: https://www.rpigear.com/ups/
Before buying this UPS I tried to install the supplied software / driver on my RPi 3B+ and HifiBerry DAC Light but was not entirely successful. Some errors have been raised.
Another topic is then connected, a big RPI case. Here I found this "TiredCube [ Raspberry 3 case ]" in Thingiverse: https://www.thingiverse.com/thing:2470712
Is there any interest in discussing this topic? Maybe this is the wrong forum ('support') and should be shifted into 'Product Ideas'?