If you start over, then you have to compare the old, working 2016 version, every file, that works for Maelstrom to the new one and add, remove, change the relevant parts again. You have to add the new native function declarations that exist in Maelstrom, but not Storm 2.0, you have to remove the native function declarations that no longer exist in Maelstrom, change those SendMessage statements that don't have the correct parameters because they changed from 2.0 to 2.8, you have to modify all the LogInterface, BattleInterface and flag things that don't work the same, the sound messages/calls that are different, etc.
There are literally hundreds of lines that need to change.