I think so--I did other side quests to get access to zones and had no problem doing the "normal", planar progression quests. Note that you do have to do the standard quest in order to keep progressing, this just lets you in quicker.
'hope that helps.
I did some testing whilst in a LDON last night. The xp bar for Leadership and normal XP's seemed to increase as similiar amounts (with Leadership turn ...
