Is a full party still "required" for leveling?

[Lolita]

Way back in the day (v6 - ??) it was best to have a full party for max exp. Is this still necessary?

[Catsy]

only when you have a leecher
otherwise it takes no effect

[Ziggi]

Link Atk gives you way more Dmg with a full Party so you Level faster.

[STRanger]

Full party with all scrolls active will grant you an even greater damage, meaning it will take you lesser time to lvl up.