I do use all Umbra warframe mods on my Rhino, Chroma, Inaros (the Umbral Intensify mod helps with the slow on the Gloom ability subsumed onto him), and Lavos. But outside of that, I really don't need them all that much to the point I need to use Umbra forma nowadays. Especially on warframes that rely on their 4th ability, which is replacing Umbral Intensify with Precision Intensify now. I use the Sacrificial Steel mod on my crit melee weapons but I don't really use my umbra forma for that.