Q: Which and how many Default Client Settings control the MDM inventory?
A: An admin can set classes on Default Client Settings - Hardware Inventory.
Q: Can the admin do a Custom Client Setting to override the MDM inventory settings?
A: An admin change the interval in UI, but it will not be honored.
Q: What is the default frequency of Inventory collection?
A: 7 days
Q: Can this frequency be changed? Are there any workarounds to expedite the inventory collection?
A: It can be changed on the Configuration Manager console to more frequently (Say 5 min or 1 day). But each device platform has a frequency to connect to Gateway.
For iOS, the only way to expedite is as follows:
This forces the inventory policy and inventory should show up in the console soon after.
Q: When a device type is changed from Personal to Company, what should we expect for all inventory to be reported?
A: On changing the device type, the default inventory collection frequency should be honored – whenever the next inventory collection schedule is set. The workarounds mentioned earlier can be used.
Additional useful information
For Personal Devices
For Corporate Devices
For domain joined (Intune Standalone Client), inventory all apps
PC Windows 8.1
Win 8.1, Win 8
For enrolled (OMADM), only Managed apps
Only Managed apps
Win RT 8.1
Thanks Vinay Bhatt for the great information!