Idle Quality Solved

[NoSparkNeeded]

My 85 300TD has always ran supberbly since I purchased it last year.
I installed new old stock Bosch nozzles purchased from a forum member.
Did a valve adjustment. Drip checked the timing etc.
However, since day 1 it has had this annoying rough idle when first
started unless I gave it a very slight throttle input. Only when dead cold. In 2 seconds or
less it would smooth out, so I just lived with it. My wife used to tease
me that her 84 300SD could start and idle cold without touching the throttle,
even though I only have 109k and she has 240k. So yesterday she
fired up her car and came back into the house and said, gee I shouldn't
have teased you, now MY car is doing that rough idle for a second when cold. I had just read a thread about glow plugs, so I got out the Fluke
and tested at the plug. 1-4 .9 ohms, number 5 157 ohms, cripes it just HAD
to be number 5. So I tested my car, yep 1-4 1.2 ohms number 5 AGAIN grrr, 0 ohms. I didn't have a reamer, but the plugs came out very easily, pulling
with just my fingers, and they had no carbon build up, so I just put new
ones in both cars. I thought about replacing them all, but after seeing that many forum members get glow plugs at junk yards, I saw no reason to "baseline" them all. I'll just replace as they fail. I'm pretty sure they were
the originals on both cars, so they seem to last a while.
Well now both cars start and idle smoothly at first morning start with no
throttle input. So was it bad not to ream, or no big deal?