Thanks. I have an E3D Hemera sitting on my desk waiting to go on my CR-10 so I can print TPU and nylon eventually. Just haven't got round to it yet
I tried it accidentally on my Ender 3 when a supplier sent an incorrectly labelled sample. It printed, but welded itself to the bed!
I use Fusion360 for design. You're welcome to this STL if you want to have a go at printing it in Ninjaflex. I'm not sure how it would behave with that though as it's designed for PETG so it locks together (to an extent). I would expect ninjaflex to require adhesive, although this requires a sealant of sorts so maybe not that different. I would make the design quite different to print in ninjaflex from the start though so I may send you a couple of STLs to play with when I have time to tweak it.