Printing troubles with FilaFlex

[curious aardvark]

with flexible filaments ALWAYS print at or slightly beyond the upper temperature limits the manufacturer recommends.
Polyflex is the significant outsider - but that's flexible pla which is a whole different animal and much more compliant than any of the tpu's
For any polymaker flament you'll find that the recommended settings are always absolutely bang on.
I haven't found this with any other manufacturer.

With the rubber based filaments - of which filaflex is one - you need to print pretty hot, 5-10c hotter than the manufacturer claims, as a minimum

The other thing that makes a huge difference is the colour of the filament. Green is hands down the best colour to use for any of the tpe/tpu filaments.
Red seems to be the worst.

I can print just about anything in green filaflex while currently failing totally in printing with red filaflex - and i bought big roll of the red after the green had worked so well.
We live and learn :-)

White is usually pretty good as the white colourant always makes any filament stiffer. Black usually also works quite well as it heats up quicker and flows better - but make sure you have active cooling in place for black tpu's

A cooling fan for your print area is also essential for small(ish) prints.

Print speed - go for 20-40 mm/s - 30mms seems to be the sweet spot. And like I said up the print temp.

Because the extruders in the flashforge printers have gaps alongside the extruder gear and guide wheel, ANY backward pressure from the extruder causes the filament to deform into the gaps, causing loss of extrusion and often clogging.
I've got the fan and heatsink removal, unclogging and replacement operation down to under 5 minutes recently :-)

So the trick is to balance the feed/print speed with how easily the material flows from the extruder.

as lambda said 0.2 or 0.3 layer heights work well. I never use 0.1 for anything anyway.
But for me the main breakthrough was in printing hotter than the manufacturers claim.

Currently looking at different extruder setups that eliminate the gaps the filament gets stuffed into.

You don't need masses of infill. But a minimum of 3 outer shells is a good idea.

Printed a little cowboy hat recently, 3 shells and layers and 20% infill worked extremely well.

So:
Active cooling
Print temp hotter than manufacturers recommend
Only ever use green tpu ;-)

Nah, just print other colours more carefully.

Also, I wanted to add (this may be a dumb question) but for the Auto-Configure Material settings, which option should I choose for using Filaflex?

Did not know such a thing existed - basically it's a total waste of space. Don't use it.
How a filament behaves is dependant on your particular printer and the environment it runs in. Always Start with the manufacturers recommended settings and work on from there.