Sure im happy to point you in the right direction. The most popular place they get discussed about and practically implemented is over on the DIY solar fourm website.

The offgrid renewables crowd with smaller battery supply who can just barely afford to put out enough wattage to run a fridge or AC are the ones who benefit most from soft starting. Then there are the nerds who like watching graphs that get off on maximizing system efficency and lifespan of their appliances.

The users of that fourm often go into technicals that I myself am unfamiliar with. Differences between motors and compressors of different phase and voltages. Its interesting to see how some people think about things.

I recommend just going through some different fourm post there related and read through what people say and what their situation and reasonings are if you want to learn more.

Here’s a post I thought a had good info.

Theres plenty of YouTube videos on the topic too.

Its one of those really niche electrically technical things that not many people have the schooling to to fully understand the theory of. The few people that have a genuine good reason to go out of their way to do it have different understanding and implementations.

I don’t mind answering questions if you wanted clarification as to how it works on a conceptual level.