If you are interested or curious about spinning, then getting an hour or two of spinning lessons in another type of aircraft will not upset your training. You will not suddenly become a rated Extra/Yak/T67 pilot with incorrect checklists imprinted in your brain.
After having a few spins demonstrated by a competant instructor, and then learning the correct methods of recovery and both the incipient and fully developed spins - you will have more confidence with stalls, steep turns and manoeuvering in the glide. If done now, before the end of your PPL, it would not harm your training. In fact, it might help it.