6.0 Red Mage speculation

[ADVSS]

Someone posted this long ago with more details but I really liked the idea and thought it would fix some RDM issues.

The proposed spell was a sort of spell blade which was a melee cast which would consume and fire/earth proc for extra damage as well as a significant amount of mana (20 or something)

That spell was not meant to be part of the normal rotation but instead meant to burn mana if some were to be in excess before a burst window (like you're at 80/85 and in 15s it's Showtime with everything coming back)
Or as a small finisher if the boss left the fight in order to consume the procs that would go to waste.
Mind you the goal was to make it "just weak enough to not spam it over regular melee".

Isnt this engagement?

I don't see it that way, since I use it between Dualcasts if Fleche and Contre are on cooldown. It's the closest thing to the type of gameplay I wanted out of RDM since there's sword swings and spells used in tandem while standing in the front lines. As a redesign is not on the table, I'd like more of that because it's the next best thing.
Speaking for myself, the benefits are that it uses the sword, it's in melee range, doesn't involve me needlessly jumping around and is not restricted by the mana bars. Also, an ability that can be used at any time isn't comparable to combo extensions, since the latter are restricted by the mana bars (along with the problem with mobs becoming untargetable or dying early and how those screw you out of the mana refunds).

As I said, my aim in asking for these things is that I get a facsimile of what I wanted out of RDM while avoiding having to do a redesign of the job (which would basically put off anyone that is looking for a caster without the SMN spinning plates or BLM timers).
We'll have to wait and see on that one. I don't see Engagement going away without the devs doing something about Displacement first. And altering Displacement means you're fiddling with a part of the "hop in and out" thing the devs have saddled RDM with, which may or may not necessitate other changes.

I am and have been pretty sure the job you're looking for is Mystic Knight, and has been. No need for a rework of RDM, just push for Mystic Knight