Just to extend my query (and this, I guess, would apply to any attempt to configure two STBs on the same scart):
If a B&O scart expander was attached to the HDR1 with two STBs with splitter and IR blaster control, presumably there would have to be a delay built in so that when one box was switched on the other box had already switched off. When using the normal splitter on the back of the TV to two separate STBs (on different scart connections to the TV) it is noticeable that a box can stay switched on for some seconds after the Beo4 has selected the other box. (In fact, on my BC1, the STB doesn't turn off for about 30 minutes if switching from the STB to the built-in FM radio tuner).
Graham
I used to be indecisive, now I'm not so sure. [W C Fields]