I wanted to get some feedback on using long lines (e.g. safety lines, long-leash, etc). Do you feel these are safe to use in places like the dog park with other dogs present? What lengths do you feel work best? 15ft, 20ft, 30ft, 50ft, etc. Have you noticed any benefits between using wide leads vs thin or rounded rope leads? Is one less prone to getting tangled? Lastly, can you think of any other tips or suggestions when using long-lines? Thanks!!!