Most of the work I do is on these old pocket watches, and I can say that getting a clean reading on a time machine IS possible, there are just a lot of things to look for. Rubbing of the hairspring is one, but the alignment of the spring within the regulator pins is a big one. The pins should not pinch the spring, it should sit between them with the tiniest of space on either side, throughout the movement of the regulator. Make sure the pins are perpendicular to the bridge, not angled in or out. Moving the regulator to its extremes should not significantly disturb the shape of the hairspring. It takes very small adjustments to get it all right, but I've done it, andI'm no where near a pro. Mark has a good video on adjusting hairsprings, I'd have a look.
Also getting the dial up/down positions aligned timing wise is the first step, and most of that is done with making sure the end shake is proper, and there are no parts binding in one position or the other. Sometimes with too much end shake the pallet fork will contact the roller table and cause crazy noise and erratic beat readings on the timer. It just takes time and patience but it can be tracked down. Here's a great website that covers the subject very well and thoroughly.
adjustingvintagewatches.com