About fillets you will have any problem to make them if you export in Step format to the free DesignSpark Mechanical ;)

Even with your "special" object! ;)



But it's a little tricky ;)
See my French site about that! ;)
http://moiscript.weebly.com/designspark.html
http://moiscript.weebly.com/designspark-1.html

or here for English people ;)
https://moi3d.com/forum/index.php?webtag=MOI&msg=6186.52