Hi, @jymm (Jim) 
About this last question of yours:
I may be wrong, but I believe the first point release (24.04.1) of Ubuntu MATE 24.04 LTS ("Noble Numbat ") will be released more or less at the same time as it will be for "regular" Ubuntu 24.04 LTS ("Noble Numbat"), so it will be on 15th of August or some time after that date (of the current year of 2024). Here's what the "Release Notes" for "Ubuntu 24.04 LTS ("Noble Numbat") say in its "Upgrades" section:
Ubuntu 24.04 LTS (Noble Numbat) Release Notes - Release - Ubuntu Community Hub
" (...)
Upgrades
Users of Ubuntu 23.10 will be offered an automatic upgrade to 24.04 soon after the release.
Users of 22.04 LTS however will be offered the automatic upgrade when 24.04.1 LTS is released, which is scheduled for the 15th of August. (...)"