Pavlova experiment

The first time I made a vegan pavlova, I was winging it, so I decided to do an experiment and refine my recipe. Here's the best version I have come up with so far:

100g flax seed goop
100g sugar
pinch of cream of tartar
2g versawhip 600k
1g xanthan gum (this was an accidental increase from the first time; I think 0.5g works too)
0.6g agar powder

1. Whip up the flax seed goop in a stand mixer with a whisk attachment. Whip it until it is very frothy.

2. Mix the rest of the ingredients into the sugar.
3. With the mixer running, add the sugar mixture a bit at a time. Keep whipping until you have a very stiff foam.

4. Scoop the foam out onto a parchment paper covered baking sheet. Form it into a circle about 8 centimetres tall, with the centre slightly lower than the edges.
5. Bake at 100 C for 1 hour, then turn the oven off and leave the pavlova in there (with the door closed) to cool completely. I would say at least 4 hours. (I typically leave it overnight.) After it's cool, you can store it in an airtight container -- mine have been fine 2 days later, but I haven't tried leaving them longer than that.
6. Decorate with non-dairy whipped cream (e.g. whipped coconut cream) and fruit.

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Some notes:

• For my first (unsuccessful) attempt at a simple flax seed meringue, I made the flax seed goop by simmering it for 20 minutes. There was a lot more than Miyoko's recipe said there would be, so I assumed that I had undercooked it. For my second attempt, I simmered it for 40 minutes. I ended up with 2/3 of a cup (the recipe said about 1/2 cup). Both versions worked fine. The version with the longer cooking time got a bit brown on the bottom of the saucepan, and this flavour carried over slightly into the finished pavlova. It was tasty, but not really authentic, so I would try to avoid it in future.
• Other people (Miyoko, various people on the PPK) have been able to make fluffy meringue using just flax seed goop, sugar and cream of tartar. I have tried twice now, and haven't got it to work. My best attempt was this very weak foam:

• It's possible that if you can make a good meringue with just flax seed, sugar and cream of tartar, then you might be able to make a pavlova by adding xanthan and/or agar. But I think I am officially giving up on that goal -- I like my results with versawhip.
• I tried a version of the pavlova with 100g water instead of the flax seed goop -- so with versawhip as the only whipping agent. The flaxless pavlova had a nice crisp outer shell, but the inside was quite insubstantial. The one with flax had a more marshmallowy inside.

Flax + versawhip:

Versawhip only: