Resolution:
The 3.0. GA adapter doc on Page 61 reads:
Wireformat             ActiveEnterprise 3.0
- 1.0.x                n/a
- 2.0.x                Supported*
- 3.0 or later         Supported

*Only supported if you have R/3 Adapter 2.0.4.

The doc mentions this under "runtime Compatibility" (i.e interoperability when a 2.x adapter is sending/receiving messages from/to a 3.0 adapter) and not as a requirement for upgrading a 2.x adapter site to 3.0 (i.e there is
no dependency from a MigrationTool perspective).

If you need the 2.0.4 adapter because in your deployment you expect to have a 2.x adapter communicate to 3.x adapter, pl. contact support@tibco.com who will arrange to send you the SDK2.3.4 dll which is the only library you will need to have these adapter components interact with each other.

[This KA was unapproved and obsolete when migrated.] Will I need SAPAdapter 2.0.4 for upgrading my R/3 adapter version to 3.x?

Product: TIBCO Adapter for R/3 (SAP) Version: 3.x, 2.0.4 OS: Not Specified OS --------------------