Arabic problem & Unicodes

An Arabic otf generated from Glyphs works fine in Freetype/Harfbuzz, but has crippled spacing in Fontfusion/Panorama, any idea what’s wrong?
By the way, zillions of fonts have more than one Unicode assigned to a certain glyph, is it correct that I can’t do that with Glyphs? Why?

Glyphs can’t do it because makeOTF does not support it. I’m working a better solution.

What is Fontfusion/Panorama? Maybe a font cache problem?

Fontfusion/Panorama is a device embedded rasterizer (2011) from Bitstream, now Monotype. I don’t have one to test myself. Not a cache problem. Maybe HMTX? We’re trying to nail down the problem. Will let you know.

MakeOTF seems built for Adobe needs only. FontLab makes several tables itself to circumvent limitations.