I have been keeping an eye on this thread and i feel a few things should be said to bridge the gap between the community and simplify3D.
How much is this "small" update fee likely to be? you don't need to give a 100% right price but you could give a ball park range you plan for it to be within, what you might feel to be "small" might not be what the community feels to be "small".
How long will the paid upgrade last, before the need for another "small" paid upgrade?
I have watched simplify3D fall way behind other slicers and most of them are free due to the lack of updates and then buggy updates when a new version does come out whats not very often one does come out, it might be of a big benefit to give access to beta versions to speed up the process of gaining feed back and finding real world bugs.
The main worry is, we will pay for a upgrade that will only bring the slicer back on terms with other slicers and then you will fall behind again and we will be faced with another paid upgrade again to get just back on terms with free slicers.