I agree 100% in the disconnection of those springs!
A case in point here....
If you buy a commercially made engine, built or modified (as most of them are) and adapted for R/C purposes, the mfgr. probably has selected a specific carburetor for the engine. In doing this, they inadvertently have gotten a carburetor with very soft weak springs. I fly only converted weedeater engines with the standard carbs. I tested this theory on my plane by not disconnecting the spring purposely. I used a standard size 49 inch oz. servo on my throttles for years. This combination during the test with the spring connected bowed my throttle pushrod so badly the throttle plate never budged!

So you are comparing apples to oranges here. It all depends on the spring's strength, whether you can leave it, or disconnect it in your given situation. Read all the variables into your equation before taking action is what I am saying here.

John