Is it unadvisable to use a Blizzard A1260 (without SCSI module attached) in an Amiga 1200 that's not towered?
The only problem I actually know about is the electricity problem.
Your question should be:
Is it unadvisable to use a Blizzard A1260 (without SCSI module attached) in an Amiga 1200 with the original A1200 powersupply?
The answer to that question is:
Yes it is undadvisable. It just isn't worth the risk of damaging things.
People use Towers to solve 3 problems all at the same time.
1. Space.
2. Electric Voltage Supply.
3. Heat dissipation.