Yes, we are aware of the fact that the js. integration has flaws with the indexation by Google.
Though Google reported 2018 that they have enabled their bots to crawl js. content, the reality is it has never successfully led to a significance.
Solution, sitemap?
We already tested shop-based sitemaps but the results were not promising.
Here´s the why: For Google, the entity of all active shops consists of an identical content structure.
Means, independent from each shop´s topic and the designs offered inside, Google Bots recognize the deeplink structure for every shop as the identic. Therefore they most likely only crawl and rank content that is really well maintained by the partner.
How to overcome this?
My advise here is clearly to use the blessing of an own domain by building user relevant content around your shop. That´s what Google is looking for.
Means, you should start building a content home. Create Landingpages for your best niche designs. Do storytelling about your shop, your brand etc.
This is where the SEO effect kicks in and where a sitemap really makes sense.
Not a sitemap for your shop, only… but for your website! That is the answer I can give here.
P.s:
Our WP Plugin makes it easy to place every product or shop page within a LP. By using the shortcode feature you can create dozens of pages, and enrich them with search relevant texts and images.