Let me preface the following remarks by saying I come from the pressure piping / vessel side of things and not the structural side, although I do find that D1.1 is a good general reference for some things.
I read through the thread you linked pretty quickly and found it interesting, but I have to say that I would never judge the acceptability of a potentially deteriorated low hydrogen electrode on the basis of whether porosity was present in the weld, or even on the results of a bend test, unless you only plan to use the electrode for misc. noncritical items in your weekend hobby shop. I usually assume that the primary reason for using a low hy process is to minimize the susceptibility to hydrogen cracking in either the HAZ or in the weld. Depending upon many other factors such as the carbon equivalent of the base metal, the weld cooling rate, the amount of joint restraint, the imposed service stresses, postweld heating, etc., a user can cross that line between crack resistant and crack susceptible with very little change in hydrogen. I have seen data from one type of test indicating that the maximum allowable heat affected zone hardness to reliably avoid cracking in a 0.35 CE steel is reduced from about 370 Vickers to about 350 Vickers when the weld metal hydrogen content is increased from less than 4 ml/100gm to 8 ml/100 gm, both of which are far less hydrogen than the hydogen present in either cellulosic weld metals or in weld metals deposited by improperly stored low hy electrodes. Best practice is to follow manufacturer's guidelines for storage and rebaking. Also a good idea to track the CE of what ever steel is used for procedure testing. With the wide range of allowable compositions in many steel grades, you might have the misfortune of testing a low CE version and then encountering a significantly higher CE version in production. If the test is crack-free and the production welds aren't anf the procedure appears to be followed correctly, then sometimes knowing the CE of test versus prooduction materials can help explain the problem.