Also they are very hardy in terms of contact- unless you dip the DVX in sand or water it’s likely to be fine without the caps should you misplace them.
Typically I have my sound person monitoring from the microphone directly rather than off the DVX’s headphone outputs and keeping an eye on levels from their own mixer.
It’s not really a filter issue but an exposure issue. The light around the flame is much brighter than the surrounding ambient light. So if you want to retain more of that very bright light you need to first close down your iris more and also bring in a heavy fill light to balance out the exposure.
Why is DVDSP better? Well I can think of about 20,000 reasons- all expressed in dollar bills you get to keep in your pocket. And it’s a way more intuitive interface.