Anyone try two different mash temps in seperate tuns for same batch?

[heathcom]

I have a recipe that calls for different mash temps, acid rest, sacc rest etc. My tun isnt the best for temp controls, would be nearly impossible to go from 135 to 165 with a few quarts of boiling water and I dont have a heater coil but I do have two cooler tuns. Would it matter much by using two seperate tuns for temps, half grains in one tun and half in the other or just stick to the usual 152 - 156 range? (depending on style of course)