Sounds like you’re early in the healing/ adjusting process so I’d recommend to avoid straining as much as possible. With time you’ll figure out balance of solids, liquids, immodiom, etc. to get stool to right consistency to avoid both uncontrollable output and straining. I’d also be careful holding it too long.
As far as how I find ways to reduce the strain and to more completely evacuate the pouch is using squirt bottles with very warm, almost hot water. I often use 2-3 refills, but in the absence of a bidet, it really feels good on the skin/ anus and seems to relax the muscles to release stool. I purchased set if 6 perianal bottles from Amazon for $10 or so. I would love a bidet, but due to issues with my pouch didn’t want to invest in one unless I for sure was gonna keep it. I am now, several years after takedown, working with a Pelvic Floor Therapist who suggests squatting first before going to toilet and leaning forward as evacuating. I also second the idea of Ilex paste, purchased directly online from company- it adheres well to wet skin and really protects, thus promoting healing. I use Vaseline to wipe it off after each BM. I know I would not still have my pouch if not for Ilex Paste! I use now mostly when area is sore/ inflamed or to hold a cotton ball/ pad up there if I’m going out. That absorbs any leakage so it doesn’t sit on skin. Geez- sorry to ramble, but hope to help. Good luck with your new pouch!
ljz