Zero,
I did the same thing for myself. I did the multi pvt after my se pvt and then did my instrument in the twin and the initial comm in the twin and my mei as my initial so it was all PIC. I used the GI Bill so my cost for the twin was around 55 an hour so I figured may as well get the multi pic then because I was uncertain if after my training if I would be able to come by any multi. Turns out at my next job I flew another hundred plus multi but I was happy with how it worked out and the lack of safety pilot time and the fact I finished all of my ratings with more than the usual 2 hours of ME pic.

The example above was what I did with my students. The twin where I taught was nearly 250 an hour so there were not too many people wasting any time up there.