Hello, I don't know if you have solved this problem. I have just encountered this problem. I was a little frustrated when I clicked in earlier and found that there was no answer. But soon I found a solution-Wechat development tool has a compilation mode, which can set up the startup page, which is very convenient. The first path to the configuration of the pages array in

app.json is Mini Program's default startup page, but this can only be a page in pages.
if you are debugging with developer tools, you can create a custom compilation mode to enter the specified subcontract page.
if you want to set the default startup page to subcontract online, I can think of one way is to create a page in pages as the startup page, and then execute a jump logic to the subcontracted page on that page.