I posted solo rounds before the rule change but have abided by the rule since it went into effect. At my prior course I played about half my rounds solo and was concerned that my handicap would be less accurate, and to some degree it was. I tend to score better by playing within myself when playing with others and my handicap dropped by about a point. I play few solo rounds since I have moved (lost the entire 2020 season due to health issues) but used them for what they were, practice rounds. I am a higher handicap golfer and to lose 2 sleeves of balls on the occasional solo round was not uncommon in 2019 since I "always went for it".