RESOLUTION 1
Attached is the script called "change collection limits" which can be use to apply to change the collection limits from 200 to 1000 (max) for all installed SQL Server agents.
To only change the collection limit for the Datafiles collection, add DBSS_File to the CollectionName variable in the script.
The script can be applied from "Administration | Tool | Script Console", click on the "Add" icon and copy and paste the script in the text block. Then click "Run".
RESOLUTION 2
If you need to change the limit only for specific agents and/or specific collections please use the script named "change limit secondary asp on specific agents collections". Here you can add agent names, collection names and different limits.
Change the following lines that they fit your requirements:
---
agentNames = ["YourAgent1","YourAgent2","YourAgent3"];
collectionNamesToChange = [YourCollection1:Limit1,YourCollection2:Limit2];
---
The script can be applied from "Administration | Tool | Script Console", click on the "Add" icon and copy and paste the script in the text block. Then click "Run".