This is great news, Henry.
In OpenACS 3.2 we simply use the compressed text type rather than the dummied large-object hack I implemented for large binary data. Users can compile PG with a blocksize up to 32KB and the use of lztext yields text columns that are even larger. The semantics are exactly the same as for text/varchar.
OpenACS 4x will be based on PG 7.1, which has no limit on the length of a text column.
In other words, it sounds like we're golden once we apply your patches to the ACS 4 request processor. OpenACS will be using the version included with ACS 4.2 beta - does the beta include your patches?