Hi! The LS1082A module isn’t shipping yet, and does not work with Pocket Reform right now due to display incompatibility (this could change in the future, but there are no guarantees). LS1028A is interesting because the module is open hardware and has more powerful cores (but, yes only two) and up to 4x the RAM of the original Reform.
FWIW, iMX8M Plus is a fantastic module (especially running an overclock to 2.0 GHz), and eliminates the need for a separate wireless card. Future upgrades are in the works with other chips and I’d keep an eye out for those as they should offer bigger performance boosts.