How to fix summoners.

[Grimoire-M]

Could you explain how you think BLM is similarly punished during downtime now?

Polyglot continues to tick while combat is paused, and with the addition of an extra charge it's now essentially a skill with 3 charges. Impossible to overcap if you're playing properly. It's a very valuable resource as xenoglossy is one of the most powerful tools they received this expansion.

They have also always been able to regenerate MP in downtime at their leisure, ensuring when combat restarts they begin with a full MP bar instead of however much they had when the downtime happened. Umbral soul makes things even more convenient, as no longer do you have to juggle between af1 and ui1 with transpose. Instead you can simply keep yourself in umbral ice, build up to ui3, and generate umbral hearts to boot. This lets you skip b4 when combat restarts, as well as enter fire with a fast f3 by virtue of being in ui3. They now regain their max output state extremely quickly after downtime because of this.

This may come as a shocker, but recovery has very little to do with it. The problem isn't BLM's ability to recover at all. Most of BLM's damage is still tied up in Fire IV itself. Downtime just naturally hurts them more, but Xenoglossy/Foul and their cooldowns still tick during that period, which are frankly minor compensations compared to what some classes get, relatively speaking.

RDM similarly loses the ability to generate and spend B/W Mana but this is minorly offset by Contre Sixtre/Fleche/Displacement/Corps-a-Corps. The bulk of their DPS still remains in their spells.

In SMN's case they now lose Energy Drains if the downtime is long enough, which effectively costs two festers/painflares as well. If the downtime occurs at the right time and is upwards of 50s in length, it can eat into Egi Assaults and more importantly, Trance windows. Either by way of making Bahamut align poorly (which you can compensate for by just blowing DWT early), or simply by delaying when you get to use Phoenix, which is the bigger deal imo. SMN still focuses on its burst windows relative to the other two casters, but SE's changes going into ShB have been targeted at their filler in an attempt to make it as important as the other caster DPS. And it shows in their numbers, for the most part. If you're getting full Bahamut/Phoenix value, using Ruin IV to move around and weave Fester/Painflare/Assaults, and keeping Energy Drain/Trance on cooldown, and always casting Ruin III otherwise, you're generally parsing well right now.

It's just numbers that are a concern, and in that matter Zerathor has the right of it. We're solidly middle of the pack. Something that hasn't been true of SMN since ARR to my knowledge.