Stuff like that irritates me sometimes, also. I guess the only thing to do is to just put a longer cable there by default or be more proactive and jump in there when they start moving the wedge.
It sometimes astounds me how some musiciansconsider the PA gear to just be "something that's just there" and paid for by someone remote and anonoumus for anyone to use - like benches in a park or something. That stuff takes hard- earned cash to buy and days and days in the shop to plan out and install in racks, label, solder, etc. And someone most certainly owns is!
I recently had a club gig where my company provided what I consider to be a nice PA: 12-box PA-system, 10 box monitor-system with drumfill, PM1D mixer, good cables, stands and mics from the "A-box" (nice mics like EV RE20, AT AE2500, Shure SM7, etc). After soundcheck one of the musos asks me: "So do you think it's safe to leave my pedalboard behind or should we pack up anything valuable?". I just pointed at the stage in one big sweeping motion and asked him "So, what do you think?"...