Ssayre
You shouldn't have too much problem getting past 27 imo, however, you will find that you reach a point where the opportunities to go faster diminish. Whether it will be the kite you fly or the location you fly in, it will have its limits. Then your personal situation may change which will also limit you.
For me, now over 50, I find it unlikely that I'll beat my grass speed. Partly because I'm now in a job that means I'm not as physically fit as I used to be; the wind speed that day was perfect for the location and the kites I fly inland (Accesses) have their own limits in terms of performance.
But it won't stop me from trying (or hoping)