ArcGis for Portal 10.6.1 ,
https://portalserver.domain.com/portal/sharing/rest/portals/xyz/update
Trying to update Max Token Expiration Minutes to 3 months i,e 129600
Error: 'maxTokenExpirationMinutes' parameter invalid

It is accepting if entered values is less than equal to 2weeks only.But more than 2weeks value is invalid.
Is it ArcGis for portal allows to update max token expiration to more than 2weeks.If yes than how, else what is the alternate solution.
Presently ArcGis for portal is configured to SAML authentication, therefore Token is created for Portal Builtin user for public use editing hence min 3 months expiration is needed.
Thanking you anticipation