Are Project Proposals and Processor equipment placed at set locations in dungeons?

My first playthrough I thought I found Product Proposals "[PP]" and CPU equipment by luck, but as I go through playthrough 2 I seem to always get them from floating blue cubes in dungeons, who's appearance does not appear to be random (nor do they respawn).

Are these items in preset locations? Meaning if I scour each and every dungeon once I'll find all of the items available in this manner?

After testing, yes, it does appear the blue floating cubes on dungeon maps (not the green ?s) are preset and do not respawn. They can contain normal items and processor equipment or [PP] items to synthesize new items.

They do reset after a New Game Plus though, so you should fully explore each dungeon each playthrough to collect otherwise-unobtainable processor parts. You can sell the extra parts or use them on more than one CPU/Candidates.

An extra sweet find: This FAQ has maps with the locations of each blue cube