Hi Jawa,
If you use single sender soap adapter for all interfaces you need to consider the problems explained in below blog.
Single Sender Comms Channel with multiple receivers - the problems
For ICO scenarios message processing using sender queues only not in receiver queues check below sap note.
1557036 - Integrated Configuration Objects (ICO) scenarios use Messaging System Sender Queues only
If one receiver having slow processing it will effect for all other interfaces uses same adapter type, check below sap note.
1136790 - Blocking receiver channel may affect the whole adapter type
As per below sap note you need to set maxReceiver parameter for integrated configuration scenarios.
1493502 - Max Receiver Parameter for Integrated Configurations
I think better to create separate channel for each interface and set the max receiver parameter then if one receiver is down, it will not effect the other interfaces.
Regards,
Praveen.