You obtain this error: "Detected a data update in the source table at version 1. This is currently not supported...."
becuse DLT is based on Structured Streaming.... and for Structured Streaming any changes (deletes, updates) in the source table are not allowed (by default of course).

Your understanding is wrong. If you use this option skipChangeCommits your 'streaming task' won't broke because of changes in the source table.

Please read carefull at previously posted link:

"By default, streaming tables require append-only sources. When a streaming table uses another streaming table as a source, and the source streaming table requires updates or deletes, for example, GDPR “right to be forgotten” processing, the skipChangeCommits flag can be set when reading the source streaming table to ignore those changes. For more information about this flag, see Ignore updates and deletes."