Viability of Flametongue for Enhance

Firstly, after the WF8/WF8 fix, I've done some auto attack dummy bashing with WF8/WF7 and WF/FT, and FT does damage equal to that of WF8/WF7 and additionally buffs spells and lava lash.

I was wondering whether it's viable in endgame gear in a raid setting, and if not, why?

Also, the glyph of Flametongue weapon. If two WF enchants aren't being used, is the FT glyph viable in an attempt to increase Elemental Devastation uptime, the same way Call of Thunder does?

It is assumed that the 21/50/0 spec is used, due to the spirit wolves STILL being bugged

Thanks in advance, Relaxx (ragnaros)

What WF8 fix are you referring to? Nothing has changed in the last 2 years at least.