Here are some very simple alternatives I've used over the years...
Over the years I've used everything from insulated coolers, heat bombs, temp gauges,and all kinds of gadgets.
I've learned that the upper shelf of a closet, cabinet, and other high shelves utilizing the 10 degree difference at ceiling level versus floor level.
Nice warm and cozy and cheap!
Fast and easy drying.
Eliminate the fans by utilizing an existing heat / air vent.
Winter and summer doesn't matter because heat tends to dry the inside of a house and air conditioning sucks the humidity out of a house. Drying times are quick!
The picture reflects a couple of small trays but you can scale the concept up easily.
I've taken a window screen and propped it up over a vent to gain lots of area.
Field capacity substrate.
A lot of people seem to have a difficult time with this and use different methods to determine field capacity.
It doesn't get much simpler then letting gravity do the work for you.
Hang up the pasteurized, drenching wet substrate in an old pillow case and in a few hours it'll stop dripping and you are at field capacity.
The picture reflects horse shit that was submerged in water to pasteurize and taken out and hung up.
If you don't have a place to drain it like a sink hang it up outside or in a shower.
These are just a few KISS tips that I've successfully used.
20+ years ago when we were moving away from the simple PF Tek I got into some pretty complex gadgets and a lot of us developed some pretty neat shit but looking back we lost sight of the simplicity that PF originally brought to us.
Feel free to post some of your KISS tips.