If you want a firmware update to fix the "taking photos truncates my GPX file" issue to get released, please contact Garmin support about it! How often do I have to contact Garmin about this? Do I need to repeat it every week? Once a month? Seems odd that Garmin wouldn't just fix something that important once they realized it was broken. We did a chunk of work to get this issue addressed but it hasn't yet become a high enough priority to drive a new firmware release. Hearing from users in the field can definitely change that. Given the technical details surrounding this issue, it shouldn't actually take very long to release a fix once it becomes a priority.
That said, if you do take a photo and your GPX file is truncated; I think tracking down the FIT file your VIRB recorded and manually assigning that to your video instead will "fix" things, provided you manually align it afterward. I have done this and it's a temporary solution. The FIT file has everything but your accelerometer (g-force, accel/braking) and movie alignment data in it. Obviously we don't consider that to be a permanent solution for this issue, but it's better than the alternative.