Proper way to manage managed-schema file

[TK Solr]

I am using Solr 8.3.1 in non-SolrCloud mode (what should I call this mode?) and 
modifying managed-schema.

I noticed that Solr does override this file wiping out all my comments and 
rearranging the order. I noticed there is a "DO NOT EDIT" comment. Then, what is 
the proper/expected way to manage this file? Admin UI can add fields but cannot 
edit existing one or add new field types. Do I keep a script of many schema 
calls? (Then how do I reset the default to the initial one, which would be 
needed before re-re-playing the schema calls.)

TK