What is the highest number of map/feature services & feature classes you have included in a single Web AppBuilder application? I believe some have posted that 25 max feature classes per app is a best practice.
For example:
An enterprise-wide front counter application "Geo-spatial Intelligence System".
Highly dependent on this issue:
#ENH-000108149 [Enhancement] Allow the option to refresh or reset a service in a web map
"Under Consideration"