Bicycle Mechanics - Requirements for use of an E-Type (BB) mounted Front Derailleur?

As far as searching goes, E-types have only been briefly mentioned with regards to BB spacing and shimanto "what does the abbreviation 'E' mean?"
If possible, I'd like to install one of these now that I'm replacing the lower workings, but I can't find a definitive resource. I've got both E-type and non-E-type bikes, but I'd appreciate it if anyone knowledgable can clear up the requirements to use one.

-E-type is mounted by means of a plate secured with the bottom bracket.
-Resulting spacing differences mean a compatible BB has to be used
-Normally used on frames with no seatpost (for whatever reason) on which to mount a clamp / braize fitting
-Is irrespective of derailleur mechanism (although I can't see a top-pull as possible!)
-Does the BB require any other mount point(s) beside the BB?
No documentation states this as a requirement, but there's sometimes provision for a mounting bolt at the rear of the BB, or sometimes where a braize-on would go
-Can an e-type be converted to band-on just by swapping the plate for a band? (presuming it's avaliable in both versions like shimanos)

Anything else that should be considered? TIA :)

As far as searching goes, E-types have only been briefly mentioned with regards to BB spacing and shimanto "what does the abbreviation 'E' mean?"
If possible, I'd like to install one of these now that I'm replacing the lower workings, but I can't find a definitive resource. I've got both E-type and non-E-type bikes, but I'd appreciate it if anyone knowledgable can clear up the requirements to use one.

-E-type is mounted by means of a plate secured with the bottom bracket.
-Resulting spacing differences mean a compatible BB has to be used
-Normally used on frames with no seatpost (for whatever reason) on which to mount a clamp / braize fitting
-Is irrespective of derailleur mechanism (although I can't see a top-pull as possible!)
-Does the BB require any other mount point(s) beside the BB?
No documentation states this as a requirement, but there's sometimes provision for a mounting bolt at the rear of the BB, or sometimes where a braize-on would go
-Can an e-type be converted to band-on just by swapping the plate for a band? (presuming it's avaliable in both versions like shimanos)

Anything else that should be considered? TIA :)

From my QBP catalogue: "Bracket type (E-type) derailleurs mount between bottom bracket shell and right bottom bracket cup. Frame must have mounting braze-on or use a Problem Solvers E-clamp."

"Problem Solvers E-clamp.
Required for mounting Shimano E-type front derailleurs on frames without the necessary braze-on.
The clamp position is 1/2" above the bottom bracket.
Seat tube must be round, not oval."

Problem Solvers e-clamps come in black and silver and in three different tube clamp diameters. Wholesale price is $9.00 so expect to pay around $18.00 from an LBS.

Thanks! Answered my main question, :) even if it's not quite the answer I was hoping for. :(
Problem Solvers E-clamp.Amazing the difference in results should you put the term 'e-clamp' into google. Some almost word-for-word copies of your catalogue description out there!

It does throw the wisdom of an e-type mount into question, having to use a braize-on fitting. After all; why not just use a braize-on type derailleur in the first place??!?

Thanks! Answered my main question, :) even if it's not quite the answer I was hoping for. :( Amazing the difference in results should you put the term 'e-clamp' into google. Some almost word-for-word copies of your catalogue description out there!

It does throw the wisdom of an e-type mount into question, having to use a braize-on fitting. After all; why not just use a braize-on type derailleur in the first place??!?

My theory is that it makes the bikes easier to set up at the factory. Lots of guys have lots of trouble setting up front derailleurs. The e-clamp sets the height and cage angle of the derailleur automatically. I think that your observation about the wording is interesting. It sounds to me like it was written by someone for whom English was not a first language.