I've created installation packages for the current state of ooDialog 4.2.3 and put them on SourceForge.
The 4.2.3 code is essentially feature complete, making the packages on SourceForge essentially what will be the beta for 4.2.3. All that is missing is the complete documentation for the new features.
Please go ahead and open up bug reports for any problems you find as though it were a beta. The official beta period will probably start at the end of September.