I think that some more clarifications are in order
I assume that when you state:
...do you agree that there are things that exist in this physical world that cannot be quantified (i.e. tested in a lab, swished around in a test tube, examined under a microscope, etc.)?
that even though all your examples refer to lab testing that is not your intent (e.g. you do not intend to exclude astronomical observations, even though a star cannot be tested in a lab, swished around in a test tube or examined under a microscope)
Secondly do you mean to exclude indirect observations, such as cloud chamber tracks ? If so then given that there is no such thing as a direct observation of any external physical object, where do you draw the line and how do you justify it ?
Thirdly do you mean to exclude things that are observable in principle but are not actually observable by us (at least at the present time) ? An example might be a distant, small dark astronomical body. For instance we cannot currently detect any cometary nuclei that are in the region of space referred to as the Oort cloud but we might be able to with improved telescopes - and of course anyone in sufficently close proximity to such a nucleus would be able to detect it with means currently available to us.