“But I think of it as a literal descriptor of what’s being eaten, regardless of orientation regarding consumption of meat and animal products.”
And there’s the problem. You may well think of it like that, but that doesn’t make it so. Veganism is specifically about reducing the suffering and exploitation of animals. It is not a diet, nor is it about health or even sustainability.
“Part time Veganism” might be catchy, but it’s wholly inaccurate.
It’s fantastic that you’ve found a way of eating that works for you and makes you feel good, it’s even better that you’ve reduced your animal product consumption. But please, don’t dilute or misrepresent what Veganism is about. You’re eating Plant Based, Part Time. Your dietary choices are not rooted in rejecting animal exploitation, therefore they have nothing to do with Veganism.
If you want to keep the acronym why not ‘Part Time Vegetarian” or “Vegetarian Before 6”?