like i said its not ideal and in no way can you ganruntee it'll work for everyone, but it works well enough on my car for me to trust it. been doing it for over a year and the motors still going strong so it cant be that bad, will be pulling it apart within the next couple of weeks to go 30det, so will have a look for any signs of detonation.
and yes a set and forget street tune wont be as safe as a dyno tune with proper knock detecting, but when doing your own tuning you tend to spend a shitload more time on it than any workshop does and you never let any knock go un checked, so in that way i find it safer. but once again everyones different