It’s my understanding that while FBX records up axis into the file, OBJ does not, so since RC is Y-up and ZB assumes Z-up, the question turns to 1) why ZB isn’t using up-axis info in the FBX, 2) seems to only allow Z-up that is recorded into FBX? Is this even the case? If you create a mesh in Blender in Z-up and export, will ZB flip that axis again or does ZB interpret all FBX as Z-up, regardless? OBJ not storing up-axis, the Y-up axis from RC is allowed to pass through to ZB. What further makes me wonder about what’s driving this issue, I encounter the same flipped axis issue when importing an RC-originated FBX into Mari, makes me wonder if RC isn’t possibly to blame in how it writes this up-axis info into the FBX.
JM, try experimenting more in Blender, generate a simple primitive like a cone in Z-up, export FBX, see if ZB’s import pref allows control over up-axis to function as expected. We should isolate away from RC to rule out a possible bug.
And what happened to DotScott1 in this thread? His plugin for ZB to automate normal maps would be so valued. DotScott1, sign of life!