Seku Im going to clear this up for you with some nice clean napkin math and that relates to having and un-synced MP drain from Darkside and MP gain from regen does not effect your ability to effectively manage your resources.

We will make this very simple and say that you have 3000 MP. (this is not the actual value)

2% of 3000 = 60 therefore every 3 seconds with this MP pool you would regain 60 MP

To my knowledge Darkside seems to be roughly a constant 3% loss while in combat.

3% of 3000 = 90 therefore supposedly you should lose 90MP every 3 seconds

so what does this mean. that you should happen that you should only effectively lose 30MP every 3 seconds or 1/100th, however because they are desynced this doesnt happen, except it does as long as the ticks alternate the mean lose 90 a second later you gain 60 you still only effectively lost 30. so as long as you dont get a down 90 then ANOTHER down 90 the fact that they are not in sych is irrelevant as it provides you with the same effective MP at the end of a cycle and i have never seen a double down. This bug is QoL not game breaking and as far as resource management goes a non issue.