So, this is how i ended up for now - i stopped using photo backpack completely, as it was not giving enough space for all the parts and was not convenient enough, for me.
so, for traveling the whole stuff sits in the hard case in the car - it is easy to transport it all this way, and hard case fits all i need - 2 chargers, 2 drones, 4 batteries, filters and props, cables, etc.
on the left is a pgytech mini hard case that fits either drone - so you can put it into a proper hiking backpack or sack and throw in the remote without a case as well, it does not need much protection. on a right is the flymore kit original bag that is used on most short hikes - fits a drone,
SC and 2 spare batteries. it has settled this way for now and nothing else is needed.
dedicated backpack did not work out as it never has enough space for rest of stuff you need to carry with you on a longer hike. waterproof hard case is way more convenient and robust.
View attachment 82172