Many Stamps UK 2020

I'd recommend people use my much more advanced Postage Pro UK 2020 instead of this app, but I've kept it updated since it still has a surprising number of users. Stamp prices updated for 23rd March 2020, next expected change for 1st and 2nd class stamps is late March / early April 2021. Do you use 1st and 2nd class stamps to send heavier letters?