I am really talking generally, not necessarily about the developer of vidblaster, which I've never used. In his case its a bit different. I think him being the only developer of the software its harder to implement things faster then a larger company with more resources and programmers. Then again if your software is popular and has many users where it justifies the extra expense of more manpower for faster development.
This reminds me of another simular case came up where an intern from Google talked about the graphic lag issue ( Like scrolling ) on the Android operating system was due to a realtime priority problem in the graphics system. Another full time programmer from Google tried to respond saying that eventually faster processors would also make this graphic lag a non-issue.
To fix this it would mean a rewriting of the Android operating system from the ground up.
Even this new Slo-Mo feature sounds like it could be more resource intensive, optimization would help, if that were really the problem.