I don't have the manuals in front of me at the moment so I'm assuming 'scenario 3' has something to do with using the dump marker to sync the replicate database with a dump from the primary ...
If you can't quiesce the primary database activity (eg, after hours, on weekend, during lull in activity) you might try:
- go through resync steps as normal
- dump primary database (this will send dump marker to repserver and cause DSI to suspend)
- load primary db dump into another ASE on the same platform (call this the intermediary db)
- make sure the intermediary database completes recovery and there's no activity, sp_flushstats (to be safe), and dump the intermediary database
- perform the cross-platorm dump-n-load with the db dump of the intermediary database
While all of the above is happening the DSI should be suspended, and as long as you didn't make any DML/schema changes to the intermediary database, you should be able to resume the DSI once you've completed the post cross-platform dump-n-load steps.
Obviously (?) keep an eye on your repserver queues to make sure you don't run out of space while syncing the replicate.