... It works great, except now Microchip has cut off the best tool for writing code for this device. ...
Microchip has stopped maintaining MPASM largely because they do not want to port it to the 64-bit execution environment of Mac OS, Windows OS and Linux OS.
What Microchip has done is offer the pic-as(v2.xx) tool chain for assembly language development.
So far Microchip has done an awful job of integration of this tool chain with MPLABX. To compound this the documentation is terrible.
The pic-as(v2.xx) assembler IS NOT COMPATIBLE with the MPASM syntax. There are a lot of odd differences that make porting MPASM code to pic-as(v2.xx) a lot of trouble.
If the only way you have used MPASM is in absolute mode you are so screwed. You will not have enough experience with PIC assembly language to even begin to comprehend what the pic-as(v2.xx) assembler is complaining about.
If you are going on to learn how to write pic-as(v2.xx) assembly language code you will need to manually add the pic-as(v2.xx) tool chain to the MPLABX environment.
Then you need some pic-as(v2.xx) assembly language examples to study.
I created a PIC10F220 project just for you. Please find it on my git repository here