I had a hot key to re-draw the lines and enable the lines for trading but that impacted every open chart. So I've adapted a different approach. You can follow my progress on Forex Factory forum, and here.
Some different features are available though;
Close of trade triggers a screenshot and saves it to your hard disk.
Sloping trendlines can be used, the prices are updated with each new bar. This means you can trade breakouts of sloped lines, or touches (stop and limit orders).
If you know how to program MT4, I welcome your comments here or on the forum.
... and I've been using Tipster Trendlines for MT4, the results of my trades are shown on the right side of the blog.