I would be curious to see if viacad could resolve this particular fillet example.
The trial I used last year didn't impress me that much. Yes you can go a little bit further than MoI, but you are still far from the last Spaceclaim video Burr posted recently.
(off course I shouldn't compare 100$ viacad to xxxx$ spaceclaim)

So far I was using an online solution like fusion360, but I hate this process so much that I prefer to waste one hour in MoI resolving the fillet 'by hand' than using this online service :P
Onshape is maybe faster to use, I will give a try (so thanks for posting the guide) ... but hell I'll love to pay MoI twice his price to have a better native fillet library !