As I am so new here if I load at 4.0 and hit the 4.1 which is max should I have any concerns?
No.
Also just out of curiosity and to save a question down the road, if I ever load at a max in this case 4.1 and I have the occasional 4.2 but with a consistent C.O.L. Should I be concerned?
No.
Reloading data is GUIDELINES. They are NOT Holy Writ carved in stone. They are NOT immutable laws of Nature.
They are reports of what was tested, and what results they got. This does not mean you will get identical results. Your gun is different. Your ammo is different. They work as guidelines because most gun and ammo combinations fall near the middle of the bell curve.
It is possible your gun and ammo combination could be at either end of the curve, (high or low) which is why we start low and test in small increments, until we know for sure. SO, GUDELINES, not laws.
Max loads listed in manuals are NOT the maximum safe limits of your gun/ammo combination, they are where the testers decided to stop, for what ever reason, and are always WELL BELOW the danger point.
Your gun will not blow up, you will not fall off the edge of the earth and be eaten by dragons if you exceed the listed max load by a TINY amount.
Your gun was proof tested by the maker at a much higher pressure amount than the listed max in the loading data. That "max" in the data is a working limit something your gun will take, day in, day out. (Assuming it takes it in the first place).
Pretty much the same thing for COAL. Tiny variations (say 0.01") in overall length generally don't matter. Yes, differences in seating DEPTH do matter, but differences in total length (case base to bullet tip) are not a big concern.
THink about it, and take a look at your bullets, AND the seating stem of your die. It does NOT touch the bullet tip. (nor, should it). It touches the bullet part way down the ogive, not the tip. (this applies to RN, loading SWC or wadcutters is slightly different)
The bullets themselves can be slightly different lengths. A 0.01" variance is not significant in handguns, though it might make a difference in long range match rifle shooting, I have yet to see a handgun where that tiny amount matters.
(the one exception is if your bullet tips are in contact with the magazine box already, then it can be the difference between binding/dragging in the magazine, and barely clearing it. A very rare thing if your loads are below the published max COAL)
Industry standard listed max dimensions and pressures are so rounds will work and be safe in everything. And they are well within the actual mechanical safety boundaries of your gun(s).