It might.
It depends on what the 4-1 diseqc switch does when you power down the humax. Does it default to one of the lnb's? If so this will have to be the 28.2 lnb, if it stays on the one it was last set for you will have to select 28.2 before you power noff the Humax. Also does the humax power down the LNB when you switch it of ( I think it will) because you will need to power the 28.2 lnb from the digibox.
You could consider going motorised and fit a quad lnb.
Or fit a quad lnb at the 28.2 position and leave the Digibox on all the time
Neil