Yup, that is a giant surfacing bit and that is amplifying and tiny tiny tram errors you have a lot. Yours actually seems to be extremely well trammed and with a 1/8" endmill I do not think you would notice. But this is common, you do need to tram to use a bit that large and it is actually pretty easy to do.
Printables you should be able to cram this on or scale it to fit your tool. Just swing it around and shim behind your tool mount between the tool mount and core to get the swing as perfect as possible. I use small pieces of blue tape, and you shim opposite of any low part of the swing on the bottom tool mount. There are rare cases where you might shim the high part of the swing on the top mount. Simple tool, does the job with amazing accuracy.