Rather than hijack another thread, I'll start a new one.
For awhile, I used quite a few Kadee roofwalks on other cars, especially pre-painted ones that had especially clunky originals or when I needed a steel one but the kit only provided a wood one. This was after I quit using stainless ones, thin as they may be, but I got tired of spending an hour and consuming a couple of drill bits in hand drilling the holes for the corner grabs.
With the Kadee ones, I at first trimmed off the little pins at the bottom of the end supports. This was a mistake, because the roofwalks curled up quickly since the pins were what kept the ends in place. So I drilled new holes for the pins, using ACC as before, and they held better. On the roof, I did trim off the pin from the center of the lateral, but drilled and filed the holes in the roof for each of the (six?) pins along the centerline. That was a fussy job, to get each one filed with enough play along the centerline that the walk would lay flat. That too took some iteration. I believe I mostly used shoe goo to hold them down, and it didn't take much.
That's the main reason why I'm a fan of the Branchline roofwalks. By the way, some more came in the mail yesterday, so thank you, Mr. Hammill, if you're reading this. With the Branchline roofwalks, I use plastic cement and hold them down with two or three stacks of stainless weights salvaged from CBT kits that I discarded long ago. All you have to do is get the alignment checked at each end before you set the car aside. Of course, I trim off the small pins and file (roughen) the space on the underside that interfaces with the roofwalk support.
For Gypsum expanded-metal roofwalks, I have a few spare Intermountain ones. They're not great, but thin enough, and I trim off the large pins. I bought a couple of the Kadee ones, so I guess I'll have to try those and the Morton ones. One of the reasons I have spares is because I threw out some P-S kits when the Kadee ones, with more accurate paint and lettering, came along. Of course I salvaged a lot of the parts other than the body. My prototype built a lot of cars with P-S ends and/or roofs on riveted body with AAR underframe, so those will get used.
Back to Kadee, even the ones on original Kadee cars curl up at the ends sometimes. Now my layout does often have the lights on all night (brainlessly forgetting to turn them off), but there's no outside sunlight to cause UV damage, and the temperature is reasonably constant, not too many days without heat or AC. I'd love to know how to cure that problem, since I have several that I'll need to replace soon, and have already done so on some cars. When the roofwalks are new in the blister pack or tube, they stay straight, including some I know are ten years or more old. So something environmental is causing it. The lights over the layout are fluorescent, mostly with one daylight tube and one cool while. They're all the newer T8 in the main part of the room.