Good question on how/when to measure your flaccid. I do not think I have seen a guideline on how to do so. I’ll share what I do.
Before this I want to make a point about the use and value of measuring. In my opinion, the value of measuring is not so you can share (brag) to others. The value is to you alone so you can have a firm base measurement to compare to. Some guys have asked how hard do I press the ruler? The answer is not so hard that it is painful. What you are looking for is consistency, so you have confidence that this measurement is done just as you did the previous few measurements.
Some guys, for whatever reason, are unable to measure at the top of their penis. They measure to the side. Again, the objective is consistency. You want to have confidence that your 1/4” gain is true gain and not a measurement error.
So back to measuring flaccid. My flaccid does change a bit over the course of the day, what I am doing and what I am wearing. I have found that a slight stretch and a gentle firegoat roll tends to get my flaccid to a more natural state. For flaccid, I measure BPFSL and NBPFL. Bone pressed flaccid stretched length is a useful data point on progress, and non bone pressed flaccid stretched length is mostly for my ego. Most of my life I was a grower and now am a shower.
Again, whichever process you decide to use just be consistent.
As to you concern that you havent yet had a good measurement, take it now and record it. Or just pick one you think is close and live with it.
You may also want to take a pic just for your future comparison. No requirement to post it.
Here’s a thread you may find useful:
How to Measure Your Penis
Initial: 7” BPEL; 6” NBPEL; 5.25” - 5.5” MEG
Current: 7-7/8” BPEL; 7-3/8” NBPEL; 8.5” BPFSL; 6.5” MEG; 6”x5” Flaccid.
Goal: Improved/consistent EQ while managing ED. Secondary: maintain current stats.