Can we make target as source and replicate to another target ? ( Cascade replication )
Need to add new target as we cannot rely on single target and we don't want to touch source for data at any cost.
You can add as many target as you can , if you have the resources required for running that many shareplex. There is no limit in level of cascading also.
If the target is going to be used as source using the same port, you may need to set SP_OCT_REPLICATE_POSTER=1 on this server so that transactions posted by shareplex is going to be captured by shareplex and cascading down to the third tier target. For more information on this parameter, please check shareplex reference guide for more information.