Are there any guidance & recommendations on customisation?
How is customisation handled during upgrading ERPNext?
Hi,
All the customization will be preserved during upgrades if you have done the customization using the Customize button on each DocType.
Another way of doing this to create your own app for the customization. This approach has several benefits like you can move the customization to new ERPNext installation easily and gives more controls through the custom coding.
You can refer this for more information: https://frappe.school/courses/frappe-framework-tutorial/learn/4.1
Thanks
Divyesh Mangroliya