""I am assuming the platten is the actual silver strip with the holes in it that "suck" the media down.""
-No it's not never take it off your printer will be parts on the ground ,it's the front cover with one hole for
paper sensor easy to remove just lose the screw you can see it.
- For feed calibration you can do it from printer menu read user manual chapter feed correction.
-the vacuum in new printer can control it from software flexi or versawork or any program others the old can't but how I remember not sure when setup sheet on machine you get choice roll -edge- piece
when set piece that mean you have 1.6 meter sheet you can pass this length in this case fan will be low.
when set edge that mean you have roll after taking width machine back it to edge.
when set roll that mean you have roll after taking width machine not move forward or backward ,in edge or roll choice fan will be strong.