I’ve never worked with the blue pads that come with the FFCP now. Mine came with Kapton tape and I could never get the PLA to stick so I just ripped it off and used painters tape and a glue stick. Worked great. BUT I saw the same issue with warping and the reason for that is that the aluminium plate wraps some when heated, and overtime it seems only to get worse.
I eventually when with a quarter inch glass plate. It is nice and flat and doesn’t warp; it is easy to prep and clean (I still use a glue stick over hairspray, I get a better result); I can also remove is and work my prints off the plate with more room and less worry about damaging my printer. Keep in mind that with a glass bed you may need to run your heat on the bed a bit higher than normal. The glass bed is the single best upgrade I’ve made to my printer, an active cooling duct and fan is a close second.
My optimal print setting with my FFCP for PLA are:
* Layer Height 0.2 (0.1 to 0.3mm depends on my needed resolution for the print, but 0.2 is my most common thickness)
* Extruder temp 200 (varies depending on the PLA, in general 190 to 210 is your range to work with, higher is gonna burn your PLA, make your prints stringy and blobby, and generally give you a poorer result. I print like 10 of the test cubes for every new roll of filament so I can get the optimal temperature for that roll, I write it on the roll so I remember it when I load it. Also as PLA gets older you may have to adjust your temperatures as well);
* Bed temp 50 (without glass 45; you can go up to 60 max. Higher than that you will be keeping the plastic too soft and it will warp. On larger/longer prints you can lower it some as well.);
* Feedrate: 50 mm/s (it can go faster, but I find I have more failures when I push it over 70mm/s and 50mm/s gives me the pest overall performance and end product);
* Travel I set to about 100mm/s. ’
Also if you are using ReplicatorG get Slic3r. People like Simplify3d also but I find that it’s detail resolution isn’t as good as Slic3r’s and that aside for the integrated GPX in Simplify3D I find Slic3r easier and faster to use.