Hello,
There is not enough technical information in your post, like what you consider to be fast enough and whether your Himalayan is broken in and what speeds you've achieved. I elected to get the Booster Plug, rather than the Powertronic offering to assist with the resolution of some idle and acceleration issues I was experiencing. I don't think either option is going to provide much cruising speed improvement.
In my opinion, the quantification of your improvement goals will help you to decide if the TEC cam replacement and other such modifications will meet that goal. There are plenty of bikes that can cruise at higher speeds, some of which I have owned. For example, a DL650 Suzuki will leave even a modified Himalayan in short order and get the attention of law enforcement in most places I've been. Again, just my opinion, but modifying a slow bike to go fast can still leave you on a slow bike in comparison to the other two wheeled options.