Pikmin disable archives trick
If for some reason the game is unable to find a file it is looking for in a Paired ARC+DIR Files archive, it will instead look for the un-archived version elsewhere in the Data Directory. This can be exploited to allow the un-archived copies of files left on the disc to be edited and recognized.
The setup is simple. First, the DIR file must be replaced with a dummy 8 bytes long containing nothing but 0
s. Then, optionally, the ARC file may be replaced with a completely empty file of the same name. Repeat this for as many Paired ARC+DIR Files archives as you would like.
It is unknown if this works for pikiSeq.arc
, as its DIR file equivalent is located in the DOL header. BUN files have not been tested. I see no way they could work anyway.