As long as you recieve the spectral vision update after burning a root it will still count so suicide tactics can be taken if you are worried about low health. You can even restart the episode if you would like as all root burning progress is saved.
For some of the roots that are out of reach, especially the one where you are supposed bail out of a car while it goes over a ramp (number 10 on Seraphim's wiki link) or the energy shield toss after reaching level 75 spectre vision, I found it much easier to use a vehicle as a platform. The extra altitude the car provides is usually enough to get the angle just right for explosives.