Dear Keith,
You don’t need to do Lama Chöpa at the beginning of each session. In the morning session, after the offerings, sit down and do extensive Lama Chöpa with Jorchö, with prostrations. Begin by generating a bodhicitta motivation for life, and recite OM MANI PADME HUM.
You can leave the merit field during the day. Don’t do Lama Chöpa before the other sessions. For other sessions do recitation of bodhicitta and the Four Immeasurables, if you like, or just do the short seven-limb prayer and the long or short mandala offering. Then meditate, following the particular section.
With much love and prayers...