We do only recommend TVOC sensors to detect spikes but not for any specific concentration measurements. For spikes, TVOC has some use cases, e.g. detecting aggressive cleaning chemicals or leaking chemicals, e.g. in an art classroom if somebody forgot to close the pot with color.
I mean, it's interesting to see the breath_voc_equivalent spiking up at night during my digestion, or spiking up after I eat beans, but otherwise I'm not getting anything unexpected out of it -- maybe my biggest discovery was finding out how much humidity influences air quality (most of the time it's almost like the air quality is a humidity inverted graph). And I suppose TVOC sensors might pick up things that your nose can't, but what that might be? Cleaning chemicals do tend to have powerful smells.
Also, for people interesting in playing with sensors, nowadays you don't have to solder, as many sensors have Qwiic/QT connectors, you just plugged them in.