I have read that azure blob storage container names must be a maximum of 63 characters long (see https://docs.microsoft.com/en-us/rest/api/storageservices/fileservices/naming-and-referencing-containers--blobs--and-metadata), but before reading this, I was testing container names longer than this, so tried something much longer:
CloudStorageAccount storageAccount = CloudStorageAccount.Parse("YourKey");
CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
CloudBlobContainer container = blobClient.GetContainerReference(@"mystorage\A2345678901234567890B234567890C2345678901234567890D234567890E234567890F23456789G234567890\AA345678901234567890B234567890C2345678901234567890D234567890E234567890F23456789G234567890");
CloudBlockBlob blockBlob = container.GetBlockBlobReference(@"blob.txt");
This seems to work fine (note upper case letters, also supposedly not allowed). I have also used Microsoft Azure Storage Explorer (v0.8.9) to open folders and files created using C# and to create more long folder names (mixed case) in my blob storage.
In real life, I was thinking of having containers up to about 100 characters (replicating a Windows file structure with five levels of folder with subfolder names up to 20 characters. If necessary, I could force these to lower case. Most of what I have read seems to suggest blob storage is better than file storage unless dealing with legacy systems or needing SMB. Based on this reasoning, blob storage sounds the better option, and everything seems to work fine when testing. However, might Microsoft suddenly impose lower case only and the 63 character limit? Is there something else I am missing?