Why would I need to reduce vibration as a rec player.They are not too stiff ... The are too stiff FOR YOU !!! And we don't know what strings and tension you are using?
Remember the ball impacts the string bed not the frame. The frame simply transmits impact and post-impact vibrations from the string bed to the handle. There are many ways to reduce the this.
Also, you might just be one of those unlucky humans whose arms are susceptible to being damaged by certain types of repetitive activities or shock.
Like you say, you may have to consider alternative solutions. But you can't blame any particular racquet vendor for your issue as there are many thousands of people who use stiff frames without any issues.
Im paying the company not the other way around, so they should do it for me.
Even pro players are going with softer setups so stiffness can be a problem for anyone.