There are serveral questions related to 'how distribute ipa without udid':
I want to focus this question to https://www.appaloosa-store.com/: ¿anyone has been capable to distribute his .ipa without including the udid/s in the provisioning file?
Note: The support people of Appaloosa did confirm that it is required a developer enterprise program enrollment. But this platform register the UDIDs of the store users, so when you upload your ipa, it automatically informs of the unprovisioned UDIDs and generates the text file to import in your developer device list. Great feature!!