My MIL is now receiving 24/7 in home care through an agency. The caregivers work in 4 shifts per day. How do I best manage them?

Finally convinced the family that my mil needed 24/7 supervision. In-laws still live in their own home. Fil soon will be 95, but is doing well. My mil is 91, has CHF, vertigo, 2 hips replaced years ago, and has back pain. She went on hospice about 18 months ago as she requires O2 at all times. The hospice nurse would come 2 times a week to check vitals and order meds and fill her medication box. She’s been taking opioid pain meds and anxiety meds for at least 15 years. Hospice took over and prescribed same pain and anxiety meds. As time went by she ‘needed’ more pain meds per day. These were prescribed, and liquid morphine added for breakthrough pain. Mil self-administered all of her prescribed meds and otc meds. She would call hospice agency for re-fills of pain/anxiety meds if she was running low. No one in the family had 24 hour oversight so no one really knew how much/what type/how often she took meds. Prior to May 2019 I was aware of these things as I had been the ‘de-facto’ caregiver in the family since June 2018. I kept detailed notes of hospice nurse visits, made sure O2 concentrators humidifiers were cleaned, filled, supplies on hand etc. I also checked her daily medication box as she sometimes would fiddle with it and mix her meds with fils. I reminded her to take the daily’s and knew when/what/how often pain/anxiety meds taken. Kept all info in binder so other family members could take over if I weren’t available. however last May I became very ill and could no longer manage my in-laws. As I had all of their info available I assumed all of the other family members would know what to do. I returned to health this fall and began taking care of these things again but noticed HUGE change in mil. Late November she fell 3 times in one week. Kept trying to convince the family mil now needed much more help. It was difficult as her sons couldn’t or wouldn’t see what had been happening for months! She had been overusing her pain/anxiety meds. She was extremely confused, weak, dizzy and just NOT herself. She was incontinent, her hygiene was poor and oral hygiene stopped altogether. I found they had no toothpaste, her electric toothbrush was very dirty and starting to mold, and she had lost an implanted molar sometime in September. I discovered she had been calling hospice and re-ordering her pain and anxiety meds because she forgot where they were for a moment. As she would receive a STAT re-delivery of them she had pills everywhere and took them all time time because she couldn’t remember! Just before Christmas I noted delivery of her lorazepam, quantity 30. The next day I found only 10. I searched the house and found stockpiles of pain/anxiety meds she’d had for years and now would feel pain, order more, then find her old pills and so on. She was completely toxic and very near overdose. After the 3 falls, and after seeing his mother unable to get out of bed, my bil called a care agency 2 days before Christmas. This had FINALLY convinced her sons (one is my h) that she needed much more help. Now we have 24/7 non-medical in home health aids They usually work in 4 shifts per day. 9am -1pm, 1pm-5, 5pm-8, and overnight 8pm-9am. I am now trying to manage her medications and ADL’s and give clear instructions to the caregivers, who are different each shift and some have had very little training or experience. As she takes meds around the clock and the CG’s cannot handle the Rx bottles I found pill boxes for each and make detailed notes and schedules. It’s confusing for them as mils med orders keep changing via hospice. Does anyone have any ideas how I can better manage the CG’s so that more medication errors do not occur? I cannot be there 24/7. Any info or suggestions would be VERY much appreciated.