Actually, remote display is possible with the base Dell iDrac Express license by enabling ssh console COM2 redirection. This is not enabled by default and not very obvious that it is even possible (probably because Dell wants to sell these iDrac licenses). For me the COM2 redirection is all that I need for a server in a datacenter without physical access. For example, if the server OS is not booting, I can still ssh to the idrac and change BIOS options or select alternative boot options in grub. For OS installs I use chroot. So really no need for an idrac license in my case.