I did buy a Switchback XT off ebay, in 50-60 lbs , for my old age and for a backup bow.
Amazing how they hold their value. Still in $400 range on ebay.
When I had a stroke eight years ago and had to completely retrain my left side, I was a couple months into rehabbing before I could even hold the bow at shooting height, let alone draw it.
I had a few compounds available, two older Browning single-cams and two Mathews I had bought used that were my current hunting bows, an LX and a Switchback. I started cranking one of the Brownings down, as I figured I wouldn't be losing as much if there did turn out to be a problem. Kept reducing the draw weight until I could draw the bow just for physical therapy inside the house. After a few weeks of that when the weather was better and I was drawing it to full draw more easily, I began shooting it in the yard. The arrows flew smoothly and were almost on line horizontally, but of course were flying noticeably slower and hitting lower as expected. I weighed the draw weight and it was peaking at 27# on that 70# Browning.
I did find one minor problem. I was still shooting fingers at the time as I had done all my life, and when I would occasionally have a less-than-smooth release, the string would sometimes jump out of the cam groove as it came to the resting position. Just not enough tension left in the system to keep it in the grooves after the shot. Easy to simply put it back on the cam with my fingers, though, so the practices continued.
As the weeks went by, and I had cranked the draw weight up gradually several pounds, I noticed that I was no longer needing to place the string back in the cam grove even after a sloppy release.
When I had increased the draw to about 40# and decided to start going to my local 3D shoots again, I reduced the draw weight on one of my Mathews from 70# to 40# and sighted it in. Zero problems with either bow, both shot smoothly and with little adjustment needed except the vertical adjustment of the sight pins to compensate for the slower arrow flight.
Still shooting the LX at practices and 3D's. back up to about 50# draw now at the first spring practices, the adding a few pounds a month through the summer as strength and stamina allows. I'll be at 60# again soon this summer. Will probably stay about there, as that's plenty for whitetails and I won't be chasing anything tougher.
Never had a problem with the limb bolts backing off any further by themselves ( I marked the bolt heads with a magic marker and checked them frequently at first, to be sure), or with the bows getting noisy, or shooting differently in any way other than the expected speed reduction. Shooting releases these days (the old finger tendons were aching pretty good after very many shots in practice, it was time).
Even the old adage about the efficiency of the bow being greatly reduced when shooting the limbs below their peak weights, is, IMO, another old wive's tale that no longer is as true as it was in the days of heavier weighted wood-core limbs and less-efficient deisgns. I know my LX was shooting my 425 grain arrows through the chrono at just over 200 fps while it was backed off to 40# peak draw, and at my 27.5" draw length, I wouldn't expect much more than that from a 40# set of limbs in a 13-year-old design.