Is your feature request related to a problem? Please describe.
From a user's comment on the Nexus website: "could you make the 'snapshot' effect and sound be configurable?
Me being slightly photophobic, I try to disable most 'flashbang'-like effects in games."

Describe the solution you'd like
See if the snapshot effect described can be disabled. If so, then have it enabled by default. But allow the user to disable it in the config.

Describe alternatives you've considered
If the snapshot effect cannot be disabled, then I don't know what else could be done about it. Needs investigating to find out if this is possible or not, and if there could be any alternative ideas.

This is now completed and has been added as part of the 3.0 release! Closing.

Isn't this just a matter of conditionalizing the Game1.flashAlpha1 (ModEntry.cs:522) and Game1.playSound (ModEntry.cs:536)?

It also looks to me like unchecking the "Show Flash Effects" game option will suppress the flash effect, but I haven't installed the mod to try it out. (I posted this suggestion in the thread on nexusmods, so perhaps the user will try it out.)