It's ok to stop vacuuming and backwash. Especially when clearing a pool. We don't recommend it on a normal basis but clearing a pool is different. Now toward the end when things are clearing up you want to wait till the pressure rises about 25% above the clean pressure.
Here's something to try while waiting on your kit to get there. Fill the pool up fairly high with water and then backwash the filter really well. Then rinse the sand pretty good and put the valve back on filter and run the pump. Hold a stocking, etc. over the return and see if you get any sand out of it. If you don't then the laterals are good and you can rest easy about that part. Then vacuum while still holding the stocking over the return and see if you get anything coming back into the pool. If you do then the problem is in the multiport and it's probably the spider gasket.
Here's something to try while waiting on your kit to get there. Fill the pool up fairly high with water and then backwash the filter really well. Then rinse the sand pretty good and put the valve back on filter and run the pump. Hold a stocking, etc. over the return and see if you get any sand out of it. If you don't then the laterals are good and you can rest easy about that part. Then vacuum while still holding the stocking over the return and see if you get anything coming back into the pool. If you do then the problem is in the multiport and it's probably the spider gasket.