It doesn’t matter where you get that passion for getting back into the swing of programming, I’m not far from your age, and truly everything becomes more monotonous over time in this life, and what was once a passion becomes something hard to achieve. In my case, AI helped me handle the tedious part of things and just kept the fun stuff of finding the solution and just tell it how to solve it, and it helps me achieve it much faster than ever before. Keep going and going! Who knows what you’ll achieve tomorrow. Keep the channel open with updates.
Whenever I throw out to the trash any electronic equipment sitting in my attic, sooner more than later is that I will need that equipment. It's Murphy's law.
You should also electrically fix your VAr, i'm not fresh with my electronics knowledge but VAr (Volt-Ampers Reactive) has no effect electrically on equipment (those are waste) because you are billed by the resultant vector of the sum of Watts (work) + VAr (Waste) = Tariff Bill
About your monitoring command:
lsof -w /mnt/* | grep /mnt/ | wc -l
Have you taken a look into incrontab, maybe it's more cpu efficient, but i don't know, so you could take a look into it.