Jumping in a little late (again). Sorry.

Regarding the question about the long term storage of caps in a fridge... I've samples from various batches dating back two years (and further), and have found no significant drop in potency (If anything, some seem to get stronger). In general, coconut oil is highly stable with a very long shelf life (so no need to wolf 'em all down at once lol).

Gelatin capsules are my preference over the vegetarian variety, as they tend to be sturdier and firmer making them easier to fill. And, in my experience, the vegetarian capsules are more permeable (from a 'smell' point-of-view), leading to the faint whiff of 'weed' being detectable even from caps stored in the fridge/freezer.

If you've experienced either variety of caps dissolving during production however, it'll be because you've: either got 'water' in the mixture, or, you've added the oil to the caps while it's still too warm/hot causing the caps to 'melt'.

Most of the oils you're likely to be using will remain in liquid form at room temperature (assuming you're not an Eskimo), so, once you've removed it from the heat leave it to stand until 'tepid' before using your syringe to fill.

Hope that helps, and.. happy baking!