Trust me, also in older versions of Microstation it's better to use dwg as the intermediate format when communicating wih Archicad. Both Archicad and Microstation have a ot of options to customize the translation process. Standardize! (that is, develop procedures and settings files that can be used over and over again). Archicad's dgn import/export has never been very useful. And Microstation can't read Archicad's .pln database files at all.
Also, be quite determined as to what you want each application to do. To import 3D into Archicad is crippled (only 3D objects are supported, you must import the whole file as one object which will end up on one layer only, or one element at a time.
Because if that and Archicad's ease of use, you'll find it is best to develop the building model in Archicad and export to Microstation for 2D and for cooperation with other MS or Autocad users. Eventually, unless you need Microstation for some external reason (client demand, cooperation with consultants etc) you'll find it can be more productive to leave it and use Plotmaker only for 2D.
This won't apply if you work in really big projects (airports etc), where Microstation still shines. There, use Archicad for specific parts and export to MS using dwg.
AC4.1-AC26SWE; MacOS13.5.1; MP5,1+MBP16,1
