you might not believe it, this is the first time I just noticed about messages for me to see this post. So here I am.
I do find the variability of all physical constants reasonable but cannot live long enough to participate in their eventual verifications.
One constant I have in mind is the universal constant of gravitation, G. My hypothesis is that it can be given by knowing the speed of light and Planck's constant.
where a is the Planck length. If the Planck length changes in time in conjunction to the universal expansion then it is very likely that G will also change in time.