With the introduction of Shinryu and Force Gauge, you can use Penelo as a solid option to fill the Gauge using her S1 or S2 as they don't deal damage but she needs Force Enhancements which cost Enhancement Points and Force Shards/Fragments.
Penelo is a stance based character - #1 priority is to maintain her buffs for herself and for the party. When buffs are dropping off usually means that you need to refresh or switch stance!
A quick note on artifacts. We recommend 108/170 for her best shaving and most damage on EX, but you can choose to go 170/330 instead if focusing on a BRV gain team.
You’ll generally want to open with a free Haste Rhumba into Evanescence to put all of your buffs & effects up. You generally want to keep Liberty Dancer active at all times, unless debuff cleansing is key for the fight. In those cases, you’ll sacrifice the auras that Liberty Dancer provides in exchange for dealing with mechanics.
Sometimes you may need to use Haste Rumba just for the instant turn rate + charge to her EX. This is needed when you are facing an enemy that has a lethal amount of BRV. Intercession will shave the single enemy to 0 BRV.
Regen Waltz has instant turn rate so it can also be used in place of Haste Rumba.
Which stance is better? It depends on the fight and your team comp! For example, if you have a strong battery you probably want the BRV Gains up from Waltz but if you have units that need to do BRV DMG you probably want Rhumba. It’s very team comp dependent!