What do you mean by "similar change"? Once checked any and all CJ-2A, CJ-2B, CJ-3A, CJ-3B and so on, ask for a change (actually, four mass changes)?

Well… Finally maybe not ask for changes would be much much easier, right? All right. It finally me cost a lot of care and time for, well, not much reward. (It appears that many of the things I'm doing here look irrelevant, useless, deletable, delayable, no? Maybe I should discretely let the big boys alone.)