Please critique my home front-end alignment method

I know this is an older thread. I have a cheap harbor freight angle finder I was going to use to measure camber/caster using the 20 degree method. My question is, what do the real caster/camber gauges do that is different than my angle finder? Does it just eliminate the need for doing calculations? Are they more accurate? I just rebuilt my whole suspension and have the offset bushings so getting ready to tackle the alignment.

Second question since "stops" were mentioned. I notice my brake hoses are pulled pretty tight when I go full right or left. Is my "stop" missing something? Or is that bolt head really the only thing that limits it?

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