I believe it’s 1% for access to the “entire post-open ecosystem”, rather than 1% per project which would be unreasonable. So you could use one or thousands of projects under the Post-open banner, but still pay 1%.

It will take years to develop the post-open ecosystem to be something worth spending that much on.

Literally just bought what I believe to be last generation’s X13 on ebay for half the price of the new one. It’s been great so far, especially with the power efficiency of Ryzen CPUs. My one complaint is the soldered RAM, which judging by the new lineup is getting phased out, thankfully.