If you mean the Open Blocks tank>Nope, if its causing lagg, it shouldn't be allowed. Simple You can use Thermal Expansion Tanks to store XP too.
However, the XP shower item does not work with Thermal expansion tanks OR Fluiducts, making conversion of LXP to mob essence impossible, crippling some production chains (especially compression dynamos). I even tried attaching the shower directly to the side of an XP absorber thing: nothing. If at the very least the shower can be made to work with a duct, the TE tank, or directly with the absorber or collector let me know.
