Replace healthy drive in RAID 10 on PERC H730

I have a PowerEdge T630 of a few years with a hardware RAID 10 consisting of 4 1TB disks.
Now I need to extend the storage, so I have ordered 4 additional 1 TB disks which i planned to add in a new virtual disk which I’d then add it to the LVM.

All existing disks come from the same batch though so I was thinking that it might be prudent to replace 2 disks in the existing RAID10 virtual disk with newer disks and create the new virtual disk using 2 old and 2 new disks so each old disk would be mirrorred by a newer disk, in both the existing and the new virtual disk.

However, I don’t find any option in iDrac to take one of the existing disks offline to replace it preemptively and i’m not sure if unplugging the disk even though it’s hot swappable is a sa(f/n)e thing to do.
In addition, i don’t know which disks belong to the which group.. so if i were to unplug 2 disks I need to be sure i’m removing a disk from both groups and not both disks of a group.

the 4 old disks and one of the new ones i already inserted in the 5th slot

available operations on the virtual disk

Any suggestions as to how to best proceed? Or any arguments for why this might be a bad idea entirely..?