Migration from IDM 4.0.2 to IDM 4.8

Hi, i'm migrating our current IDM servers to IDM 4.8.x so i have some questions about it. We have 8 active servers with these configurations:

1 Master - IDM 4.0.2 + eDir 8.8.7 (SRV01)
1 R/W - IDM 4.0.2 + eDir 8.8.7 (SRV02)
2 R/W - IDM 4.0.2 + eDir 8.8.7 + UA 4.0.2 (SRV03 & SRV04)
2 R/W - IDM 4.8.4 + eDir 9.2.5 (SRV05 & SRV06)
2 servers pending for installation R/W -> IDM 4.8 + eDir 9.2 + Identity Applications 4.8 (SRV07 & SRV08)

I've already moved all my driver configurations from SRV01 & SRV02 to SRV05 & SRV06. I won't migrate UA 4.0.2 to 4.8.x so i will install IA from scratch on SRV7 & SRV8.

My Questions:

1) I've deleted my RootCA on SRV01 and create a new one on SRV05, renewed default certificates and rebooted the server. Now i have an error when I try to add SRV07 or SRV08 to the tree. Host server is not missing in the CA Object and i've created some certificates with the new CA. I've opened an SR but i'll appreciate if you have some references about this error.

Configuring SAS service... Failed to configure SAS service: no such entry err=-601
ERROR: ndsconfig return value = 74.

May 11 15:25:15 SecurityInstall: Returned from pkiInstallSetPorts.
May 11 15:25:15 SecurityInstall: Error from pkiInstallCreatePKIObjects (ccode = -601; retval = -4).
May 11 15:25:15 An error occurred while configuring product SAS. Error description no such entry.-601
May 11 15:25:15 NDSIInstallDSProduct: Returning -601.
May 11 15:25:15 DHModuleInit_dsi: Returning -601.

2) I will leave SRV03,SRV04,SRV07,SRV08 in coexistence for a while, it would be a problem if i remove SRV01 and SRV02 from the tree and change SRV05 as the new Master Replica? SRV03 & SRV04 don't use secure connections to eDir.

Thank you in advance for your advices