If you mean the original choice of April 30, Yes. The tax year ran to April 5th back then so April 30 was the most efficient choice of date staying within the convention of drawing accounts to the last day of a calendar month.
If you mean the change of date, No. Doing it from 2019 just corrects the imbalance caused by puppy dole. It won't have much significance beyond that and the requisite revision to 2018 is similarly insignificant in my case... I've only done back of envelope figures but I may have to pay c.€42 extra for 2018 in return for which I may qualify for the higher rate of puppy dole so if the actual figures comply with the ball park it would actually be a win, win, win, win, win situation.
Conversely, doing nothing would cost me the guts of 4 large in 2021 - on foot of 2020s return. In fact it'd be the first time since I became self (un)employed that my liability would run to 4 figures.