I have a 3D45 and have successfully printed NinjaFlex however it took some adjustments which I will list below. One important factor is to minimize the resistance in the filament path. The NinjaFlex spool will fit inside the printer but the center hole is too large and the spool will drag on its od. I have printed bearings to fit the spool id using Airsoft BB's to minimize spool drag. To minimize filament drag with small prints I will sometimes assist by puling excess filament above the feed tube. I have found the following settings to produce good results with great layer adhesion.
Hot end --245C
Bed -------50C
Flow-------115 to 118%
Fan -------100%
Speed ----20 to 30
Layer-----.12 to .22 mm
I found the average filament diameter to be ~1.74 mm and used it in my settings.