Now that there is a limit of 3 blessings AND Warp Anomalies continuously happen based on your current heat I think it's time to add a new perk or mastery that makes Blessings Permanent. Duration increases are valuable for teamplay with the mastery that lets you share your blessings. But solo player it's just quality of life.
You're not going to run out of blessings in any major battle because you're just going to refresh them before going in. I don't find refreshing the buffs periodically to be compelling gameplay and when self affecting duration is not a relevant balancing factor so I don't really see a point in them being duration limited when self affecting only.