The problem is the 30 sec delay is needed only when the
DVD startups, but the delay is needed for TV. Here is
another idea where the 30 sec delay will only be invoked
when needed.
1) Teach the TV "InputHDMI1" command to the DVD device.
You will need another learning remote if the TV remote
does not have a discrete HDMI button.
2) Set the Power On delay of the DVD device to 30 sec.
This means after sending the power up command to the DVD,
it won't send it any more command until that delay has
expired.
3) In the DVD activity startup macro, select the DVD device
(not the TV) and add the learnt "InputHDMI1" command.
Don't need to add any delay here.

So on a DVD startup, the "InputHDMI1" command will be
sent (for the DVD device) 30 seconds after the DVD power
up command. On regular activity switching where the DVD
is already on, the DVD activity will also send the "InputHDMI1"
command but without the 30 sec delay. This won't hurt
anything since it's a discrete command and that is the
TV input you want anyway.