SharePoint online root site health and performance

[rnd_rnd]

Dear SharePoint experts,

I need an advice on SharePoint online root site health and performance.

We have recently replaced the classic root site in our tenant with a modern communication site.

Before doing the replace the admin center required to run the "Page Diagnostics for SharePoint tool" on the new modern site. The tool came back with analysis results that required attention i.e. Large images and Requests to SharePoint. We have fixed those issues and have successfully replaced the root site.

Since the swap is now complete, 

- can the site owners update the root site home page with large images or SPFx webparts that make multiple number of calls to SharePoint.

-will they get any warning or notification if they try to do so.

[#2 · Accepted solution]

1. Yes!
2. No

So what can be limiting is number of calls to SharePoint, which can be throttled if to many, as well as to many search queries on a single page.

Limits:
https://learn.microsoft.com/en-us/microsoft-365/enterprise/modern-portal-limits?view=o365-worldwide