The vendor must know WeChat Pay categories, review material and a shared backend — not only a pretty storefront theme.
Anyone can skin a catalog. Fewer teams can explain refunds, multi-store stock and what happens when WeChat rejects a category. Ask for that walkthrough before you compare page templates.
International buyers need a vendor who treats WeChat as a regulated channel, not as "another React target". Login, templates and nearby storefronts are constraints, not plugins.
Scope freeze, source, defect window. Mini programs fail the same way other software fails: verbal extras and no permission matrix.
They can design UI. Merchant category, pay and review usually need a China-capable delivery group. Ask who holds those accounts.
If you can live inside its checkout and you have one site, maybe. If stock or settlement is the product, custom is the honest v1.
Prefer one ID space. Two vendors with two user tables is how membership splits.
Ask a vendor to explain pay, category and the admin before you compare themes. Continue at /en/miniprogram/.