MDMI11 — Must all implementations have a design-time activity?

Current text
In particular, an implementation needs to support a design-time activity with all of the steps involved in generating the conversion maps, and the runtime application of the generated maps to a source physical message in order to create a target physical message.
New text
SEE QUESTIONS & COMMENTS IN NEXT COLUMN
Rationale
Must all implementations have a design-time activity? Don't we expect to have more implementations that use the conversion maps than implementations that can create the maps?