I think the AIO v2 needs to be updated again so that songs that were removed after 20200203 will be playable again. Song data (jk.arc, xwb, m2v) that needs to be removed (and be revived in music database) inside AIO v2 are the following:
belv, bref, haph, houk, iwyl, mawa, mont, moro, onra, rinn, roku, shut, tool, wake, & yoja
For thumbnails, delete the following in AIO v2, so that data from 20200203 will be used and thumbnails of the mentioned song above will be revived:
- jacket_thumbnails_ja_15.arc
- jacket_thumbnails_ja_17.arc
- jacket_thumbnails_ua_12.arc
- jacket_thumbnails_ua_17.arc
For U version, just copy jacket_thumbnails_ja* and rename it to jacket_thumbnails_ua*
... and this is the 20210804 startup.arc modded to revive those missing songs above. I used 20200203 musicdb.xml as base, removed DDR A20 from list, then added DDR A20 and DDR A20 PLUS from 20210804, loaded 20210804 startup.arc then updated new musicdb.xml and repacked startup.arc.
20210804_startup_arc_modded.zip