I agree with the whole adults automatically dropping IQ as soon as they reincarnate but in this case, I believe it's just because their magic system is that complicated. It isn't the "I can feel mana, I can use magic" type, they talk about formulas so they probably have to go through a lot to...
You can just find this series on other aggregators, it's not like MD is the only source, lol. And that goes with every other series, really. Unless they're also being translated by other MTL groups where both ED and TL is bad, I'd rather just read on aggs. Not naming any of the aggregator sites...