Did follow-up which had label at both ends. Works fine. V2019 Pro. The formulas are placed in the PinX and PinY cells as initially provided with the cadet that my initial master ID was different. Dragging and dropping onto stencil, and then dragging master and dropping onto page created no ref issues.
The only issue I see is a needed parent to local scaling issue. The values translate incorrectly, but that would be expected. For the beginning point this is not an issue sInce 0 = 0. But the end point is impacted.
Croc's suggestion of doing the valve in two User cells might be better form, but seems unnecessary.
If you manually move the labels after dropping, that will clobber any formula in the PinX and ping cells. In that case, use the Guard() fcn to protect the formulae. But that will prevent Manual placement. If such an option is desired, then the SETATREF() fcn are needed as they intercept & use the manual placement, updating rather than clobbering the formulas. In addition, I would add control points to allow easy placement. You had an earlier post that I provided a link which does all of this...I think.