You can read about the 2 LIFTMOR trials to learn more about people with OP lifting. Over the course of 1 or 2 months the people in this random control trail build up to full movement and full weight of 80-85% of each person's own personal 1-rep-max.

But all of the exercise was done under close supervision by experts. The most important thing is to lift anything, including just yourself, with proper form. Slowly building up the weight and movement is also important. Because you are working with a trainer you most likely know all that and keep that proper form, but I mention it for anyone else reading this tread and to keep it in the forefront of my own mind.

Since starting to do more free weights at the gym I find that it is more "automatic" that I do things outside of the gym in good form. Formerly I thought I was careful, but I had to remember to be careful. After all this practice in the gym I now have "muscle memory" to keep a straight spine and not to twist at the spine when lifting any weight, including just my own body weight. For example, in yoga classes I no longer come out of a forward fold using the "roll up from the spine" that the instructor sometimes cues.