migrate from serie I to R. Cluster LTM-GTM

We currently need to carry out a migration of six 2600i devices to 6 new 2600r models. There are three Active-Standby clusters at the LTM level. In addition, four of these devices form a cluster for GTM-DNS.

I would like to know whether you have any specific procedure for this type of migration. We would also like your recommendation on whether to perform the migration of the four devices within the same maintenance window, or to migrate them in pairs, allowing two devices from the i series and two from the r series to coexist in the same DNS cluster.

Additional information:

The source and target version will be the same: 17.5.1.3

We will use Journeys for the configuration conversion.

On the other hand, would you keep the management IP addresses of the I series on the R Series chassis or tenants, or would you request new IP addresses for all? What steps would you follow during the migration window?.