While laying flex track years ago I discovered a method for keeping the rails parallel at a joint. If not carefully laid, flex track will “kink” at a joint in a curve. To combat this, typically you hear of people soldering the joints before bending the track. I typically don’t like to solder my joints, as I often change the track around and soldered joints would make this very difficult.
I discovered the rails will stay parallel if the joints are offset or staggered. By carefully removing a few spikes, rail joiners can be offset. Here is an example of such a joint. The joints are separated by about an inch or more. If very careful, you can accomplish such a joint without removing any ties. This prevents you from having to glue them back in later.