Brian, I do not keep them in lieu of one with a good inlay. I keep one of each. I have a file for off center inlays. They have to be pretty far off before I keep them. I hesitate to call them errors. We all collect different things, offcenter chips is one of me collecting habits.
I am an error collector. I have quite a few with different denominations on each, one sided chips that should be 2 sided, spelling errors, etc. BTW, I have two error chips of Gregs, 1998 Cyberguide to Casino Chips, chips.