I'm finding thermal management guidelines for i.MX8MMini.
I found only following document but it's for i.MX6 series.
Is there any document for i.MX8M series especially for i.MX8MMini ?
There are no specific thermal management guidelines for the i.MX8M series processors.
As the basic concept, the application note document you're referring to is applicable to i.MX8M series processors as well.
There is no specific thermal guideline document for i.MX8M series. As per i.MX 8M EVK Board Hardware User's Guide, "the EVK thermal design was performed for a typical use case. Ensure your thermal design is based on your specific use case."