Do not show refit menu on boot (only with option key)
I suppose the smallest timeout possible (1 sec) would be a kind of solution, although not exactly what you wanted.

If you have another OS installed on the internal HDD that can be booted by the stock Mac bootloader, you could install refit to the corresponding partition and bless the OS X partition. Thus, when you need refit/ind, you hold the alt key during boot and select the partition where it's installed.