I'm in england :-)
The forum might be based in the states - but a lot of the members are from different countries.
England is Currently still a part of europe (till june). So postage should be pretty cheap.

Ill happily test your filament, tested pretty much every other flexible filament around.
One thing I have found with the tpu based filaments is that it depends a lot on what colour the filament is.

Green tpu will usually work great - no matter what brand.
red tends to be a lot harder to print with and black is a complete nightmare.

The colourants seem to effect the printing temperature a lot more than they do with something like pla.

But yep, send me a sample and I'll run it through the flashforge - got a number of designs I use flexible filament for so can easily do comparisons.
But yep a slightly stiffer filament should be better.