Vegan here. Interesting question! I think you're going to get a different answer depending on the vegan you talk to. Personally, this is the definition of veganism I subscribe to:
"Veganism is a philosophy and way of living which seeks to exclude—as far as is possible and practicable—all forms of exploitation of, and cruelty to, animals for food, clothing or any other purpose; and by extension, promotes the development and use of animal-free alternatives for the benefit of animals, humans and the environment. In dietary terms it denotes the practice of dispensing with all products derived wholly or partly from animals."
By that definition, for me, it is not vegan. If the VFT has been grown by humans, and fed insects, then that is non-vegan, because there was a lot of animal suffering that went into growing that VFT. Furthermore, VFTs are not required for sustaining the human body, so the only reason to do this is for human pleasure or something.
Edit to add: if the VFT was found in nature, I probably still wouldn't consume it, because 1) I don't even know if VFTs are edible 2) if they are, I've got better food with me that probably caused less animal suffering, and are less morally ambiguous.
You could look at logrotate if you don't want to do something custom