BioDieselNow - Renewable biodiesel fuel

ATTN: Apologies in advance for flogging this long-deceased equine. This is a personal inquiry stemming purely from my curiosity, and probably not useful to the community as a whole. The discussion started here.  

    This discussion seems most relevant to the commercially-made Biodiesel, where residual sub-micron particles of Magnesol are quite low (<5ppm?). Such would be the case when pressure plate filters are used. I've not heard of any home brewers that claim to have met this count - chime in if you have and share please.

    Assuming such a ppm count is met, what are the effects of the remaining traces on the fuel system and engine? The particles will be coated in glycerol after use and will be sub-micron (in general), as only the smallest particles are likely to go uncaptured.

    There are obvious problems, like the individual particles collecting into large blobs of glycerol, and clogging the fuel system. These issues are fairly well documented when large quantities of free glycerol are passed through the system, though we're referring to trace amounts. Would regular maintenance, such as period filter changes, handle such problems?

    Fuzznag brought up the ASTM D6751 standards. This would affect those trying to achieve specs, though not home brewers. For those wishing to meet the spec, filtering is definitely critical. As is, this has nothing to do with effects on engines or fuel systems. I haven't read why this particular standard was adapted, but if someone can elaborate, please do.

    I'm not sure what the injector nozzle tolerances are, but other engine component tolerances that I could find are notable greater than 1 micron. Wouldn't this eliminate wear due to friction? Disappointingly, I've seen no follow ups to the original ISU Magnesol study discussing filtering, or effects on engines and fuel systems, and they make little mention in the article. What little I have came from a publication from my library that states (on Pg 18 of 28), "the effect of ... free glycerin content on fuel lubricity is unknown." This seems relevant, as the particles in question would be coated with glycerol (if the surface deposit were still active, i.e., unoccupied by glycerol, the particles would be attracted to other trapped contaminants in the filter).

I'm trying to understand this as best as possible, so if you have more up-to-date information on this, please pass it along.

Side note: I'd add, my experiences with Magnesol have been "mixed." I would certainly remove the selected contaminants from the fuel, but filtering was a huge pain. If a seam ever leaked on a filter, you may not notice, and residual Mag would definitely be a problem. Too risky for me, which is unfortunate, as we lack the water supply to use the conventional wash.