As of today, only BigIP F5 is supported replacement for WAP servers.
To be a supported replacement, the product has to comply with: https://docs.microsoft.com/en-us/openspecs/windows_protocols/MS-ADFSPIP/76deccb1-1429-4c80-8349-d38e61da5cbb
If not, some features will be broken.
You can use NetScaler to load balance your WAP and ADFS servers, but not to replace them.
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