I had an opportunity to download a fresh copy of FactorLib 1.8 onto an OSX laptop, and connect it to the PitchFactor. So that's what the Edit Console looks like! I had a go with the renaming process for custom presets. Still no joy, although it did work on renaming the remaining factory presets. As reported elsewhere, I had to switch away from the sent preset before the renaming became visible. But I did find a workaround for custom preset renaming:
If I named a custom preset *anything at all* (Preset 1:1 named "Z", for example) from the PitchFactor itself, saved it, then brought it into FactorLib for more text editing, the returned custom preset's renaming 'stuck' from there on out. Transferring all 100 presets back & forth was (subjectively) more reliable than sending / receiving one single custom preset. Occasionally, I'll "get" two complete uploads (100-preset untitled .syx files) from a single Open From MIDI command.
Here's where the process diverged from the WinXP – SP3 experiments earlier. When I uploaded all 100 presets (mixed custom & factory) to the FactorLib, and Save to Pedal immediately, I ended up with those "weird characters" reported earlier here. Only on custom presets, and on every one of those (custom). It seems to be some variation on program change number, plus some value. By way of example: 1:1 was renamed  1 3. 1:2 was named  1 3. 2:1 was renamed  7 3, and 50:1 became  3 3.
Stranger still: Two or three consecutive full dumps to FactorLib resulted in 114 presets! The "extra" 14 presets were all named "Preset 1:0". Just to prove to myself that this was no illusion, I performed a Select All and tried to send everything back to the PitchFactor. The warning message "Cannot send more than 100 presets" popped up. The third time, I watched the PitchFactor display. Only 100 presets were sent, but 114 presets were "received".
So, moderate success in OSX, and slightly less in WinXP. Note that the Eventide Update Utility would not work for me without SP3 installed. Now, on to the next O/S … For those keeping score, an informal sampling of forum responses has Win7 users reporting the minimum amount of "anomalies". But the issues here deal mainly with custom presets, and I don't know if the Win7 users were 'all factory', or a mixture of custom / factory presets.
Definitely there are changes made to any number of parameters in a custom preset. I'm trying to determine whether that's FactorLib 1.8, PitchFactor's beta, the host operating system, or some combination of the three.