Blanking them won't get rid of a fault though. It will stop the gas going into the inlet but if the EGR is showing as out of range or faulty in whatever way, that will remain. The only way you can get rid of that is to code them out but even then it will still show a fault if scanned but it won't cause a "restricted performance" mode on the car while driving.
Mine used to smoke really badly under hard acceleration when I got it but I bought it broken and found the split inlet manifold. I have no idea how long it had been driven like this prior to my ownership and whether it had just been gently pootled about for fear of limp mode. Once I'd fixed the issues with it, the smoke stayed for quite some time but it did lessen and now I only get a bit of grey/brown when I make it work hard as you'd expect. Recently I had some issues to work through that meant it spent a lot of time on short runs and idling for extended periods so naturally it did smoke a fair bit when I started using it properly again.
I guess where I am going with this nausea is that if you aren't seeing a performance issue or any faults, get it out on some long drives and see if it starts to clear up, you may be looking for an issue that doesn't really exist. Is the P023D back since you've swapped the Map sensors about?
Why not take the EGR blanks out and see if the P023D goes away and your EGR fault returns? You have one less bolt to undo than anyone else
. I love that it was fine when the guy did it but mysteriously the bolt just sheared off!