SUMMARY Baloo currently does a decent job at not hindering the machine ability to quickly perform other tasks by running when other tasks don't need resources. Still this could be very much improved by also looking at the thermal situation of the machine. Baloo should avoid making the machine temperature rise high enough to make the fans spin loudly (let the laptop remain silent, please) and, even worse get the cpu in thermal throttling.
See also... ... Baloo Read Throughput was 500Mbps up to 1Gbps, this is not bad, but SSDs tend to overheat easily on sustained reads/writes, and Baloo was doing this for a long time ... https://old.reddit.com/r/kde/comments/w49vko/advice_be_careful_when_adding_tons_of_files_or/
Won´t do. 1. There are other programs which cause even higher CPU load, also not considering system temperature. 2. "High Temperature" is subjective. Fan speeds are not universally available. Some systems will have Fans always running (slowly), while others stop Fans completely.