Is there a way to force the second stage heat to come on all the time?

I don't know your reason for this but you can put a jumper wire from W2 to Y1 and the aux heat will be on when 1st stage comes on. Remove it when in summer cooling mode.

Thanks.  The reason is too put more heat in to reduce the time to get to temperature.

I'm not tring to be smart, but if I were you I would just put the thermostat in emergency heat mode so the heat pump would not run. That would save you some expense on the power bill although not much and also provided you have enough back up heat to heat your home.