I played a lot of SCH in dungeons before Stormsblood, and MP was never really an issue. But now, when I try my usual playstyle, the MP gets used up very quickly. That's when I realized the design philosophy the devs may have been going for healers: making shields prohibitively expensive.

Using Lustrate to supplement the harder healing phases is fine, but the SCH's lack of a readily available mid-grade heal is a missing part of their bread-and-butter toolkit. Since 2.0, Adlo is the only stronger cure spell available to SCH, so some players may treat Adlo as the SCH-version of Cure II, which will really tear into their MP now. However, instead of just making a "Physick II", let's it more unique to SCHs:

Emergency Tactics: Same effect, and lowers the cost of Adlo and Succor by 25-50%, its CD time is lowered to 15 seconds.

With this ability, the SCH will have their own version of a Cure II and Medica that doesn't get in the way of the design of having a costly shield.