Is it safe to keep the KeyVaultClient for long?

[ctthang]

Hi,
I have a question regarding to the disposability of KeyVaultClient:
The KeyVaultContext struct keeps a KeyVaultClient for its internally SignDigestAsync and DecryptDataAsync, then the RSAKeyVault keeps a KeyVaultContext inside.
All the "ToRSA" extension method constructs an RSAKeyVault with a KeyVaultContext, which means the KeyVaultClient should live along with the RSAKeyVault.
if the RSAKeyVault is used in a "singleton" manner, then it is impossible to dispose the KeyVaultClient?

Is it safe to keep the KeyVaultClient for long? a whole lifetime of the w3wp process for example.