Upgrading .NET Framework version on Self Hosted agent Azure DevOps Server

Hi,

We are planning to upgrade our current .NET frame work version from 4.6 to latest version ( 4.8 or 4.7.2 ) on our primary Azure DevOps agent server(Windows).

Please suggest us on below queries: 

1.  Is there any impact on our current Azure DevOps agent setup after upgrading .NET Framework ?

1.  In existing setup, we are having single DevOps agent server, what are the risks/challenges will be there on windows server after upgrade activity ?? 
2.  If we are proceeding with Framework upgradation, What are changes required on existing Azure DevOps/pipelines setup to compatible with latest .NET framework ??

Azure DevOps Server Information:

Azure DevOps Info:

• Version Dev18.M170.4 © Microsoft Corporation.

• Self Hosted agents 

Kindly help me on this

Thanks,

Ravi