I expect that most of us who start out on a practice set, later add drones and finally regulators experience problems in getting all parts of the instrument into good playing positions. I certainly did, once I got my regulators. No matter what type of shoulder strap I set up to pull the stock up, I wound up often inadvertently hitting the higher regulator keys while using my bellows, while simultaneously having problems reaching the lower keys.
I considered shortening the mainstock, or moving the mainstock tie-in to a different spot on the bag. Dublin piper Donnacha Dwyer proposed a simple solution, however, when I discussed the problem with him: adding a longer tube between the bellows and the bag.
Once I installed a rubber hose about 1 1/2 inches longer than what I had previously used, the problem went away. I don’t have to fight with my regulators any more (although PLAYING them in a musical manner is quite a different mater). I still use a shoulder strap, but it now functions much better to pull whichever keys I need to press into reachable distance while keeping the regs out of harms way of my pumping.
The point is that the length of tubing between bellows and bag seems be a major factor in making a set really playable. This might be worth experimenting with, depending on a pipers girth, height and length of arm.
Anyone else with similar experiences?