I wasn't aware of the hentai difference, I thought we were the same on that front (I'm up in Scotland). 
As for the second bit - I lived that, yeah. There was a bit of a hoo-ha about when my sentence would be spent as I got 3 years notification requirements, 120hrs community resolution (to be completed within 6 months, this was extended to 12m due to COVID restrictions), and to complete an SO treatment program. 

The spent sentence issue was due to me given generic registry requirements and restrictions when I was charged in February, then officially put on the registry in court when I pleaded guilty in December with a lot of those prior restrictions removed thanks to my solicitor arguing their relevance, and then the final set-up when I was sentenced on the following February in 2020.

Two legal differences between England and Scotland that I became aware of recently. The law that bans possession of explicit cartoons and hentai in England and Wales does not apply in Scotland. When the Coroners act was passed in 2009, the legislation was not duplicated north of the border. That means it is still a free country, in terms of that thought crime anyway.

Second, the Community Payback Order, which applies only in Scotland, has different rules, when it comes to time on the SOR. A 3 year community order in England and Wales would mean 5 years on the SOR, but in Scotland you only stay on the SOR for the length of the order, so that could mean just 1 year.