Guys, This subject has come up a few times now and the "solutions" aren't always appropriate.
Brakes should always be in tension and never in compression. With a long rod in compression, when you apply it hard it will bend and buckle. That's just how things work. The only way you can safely get away with a rod in compression is if it is very short and very stiff.
For example if you had the original lever, suitably shortened and linked the new lever to the stock one with a short straight stiff rod, that would be fine.
The relationship between the lengths of the various levers is also important and cannot just be changed without consequences.
A brake lever also needs to have a positive stop arrangement that sets the angle and it also takes up excessive free play.
On that bike in particular and on most bikes in general, you have two good choices. Convert to a cable pull arrangement or link to a shortened version of the original lever. Bent rods, long push rods and poor linkage geometry are not suitable alternatives. We are not talking the finer points of good engineering design here. We are talking about what works safely and what does not.
There are examples of good, well though out rear sets on this site.