No, Spline mode should mainly be just smooth transitions between command waypoints, not sharp navigation. It is settable easily via Mission Planner, I’d have to dig into Solex to see what the equivalent setting is to ensure pictures are taken on turns/out of Area Of Interest/Overfly.
Yep, higher is generally better, so you have more likelihood of extracting good tie-points.
Overlap is free, provided you’ve got good storage. I’ve had no issue writing 12MP GoPro ProTune JPG to 32GB SDHC reliably at about an image every 1.25s. So, set your overlap/flightspeed to ensure you’re not collecting a photo faster than that.
Sidelap costs you flight time, and that is what you really need to manage carefully for.
Correct, from @smathermather-cm’s documentation, about 5deg above nadir (85deg down) is optimal.
I think the recommendation for overlapping survey is closer to 20deg offset, though I think he might have new guidance on that.
I never got a mission to resume haha.