How to validate the accuracy of touch actions for scrolling on a mobile device?

My scenario is to scroll to somewhere in the middle of the page, to an element which is dynamic. Now when I use touchAction using :-

TouchAction tc2=touchAction.press(PointOption.point(startX, startY)).waitAction().moveTo(PointOption.point(endX, endY)).release().perform();

The amount of scrolling is inconsistent, sometimes it over scrolls and sometime it underscrolls. Also we do not have a boolean return for touch action to know wheather it has actually worked or not.

Q1.How do we validate wheather or not TouchAction is working correctly or not?

Q2.Which is the best way to implement scroll for mobile devices using appium?