Welcome aboard
Yep, they crackle and pop for the first few hits. But, it really is not isolated to RDAs, high wattage, or low ohms. The sudden change in temperature causes the juice to start vaporizing very quickly. The reaction can be somewhat violent and trapped vapor can build up in the wick(s) and result in a pop. I build my KF @ 2.5ohms and vape at about 7 watts and have had strong pops after having cleaned and re wicking,