Rolf,
I have a CZ550 Safari Classic in .404Jeffery, it did have a feed issue initially - but was solved by a tapered spacer block in the back of the magazine well.
Perhaps a stiffer magazine spring would have been as effective but it is a point to check.

Yes mine does easy 4 down (5 possible for the .458Lott)
Stock design is comfortable for me being just over 6' tall, my handloads are just over the 2320fps so not hot, but you certainly know they're not soft loads!
85gn AR2209 with 400gn Woodleighs shoot 1" high at 50m in my rifle

I got this red dot mount below from AHR in the US (They are very good to deal with & most helpful), I coupled it with a STSB-3.5 STS Red Dot Sight. This system works an absolute treat & is easy to load quickly without getting hung up on your scope; it can be removed very quickly & stowed in your pocket easily as it is rather small!
https://americanhuntingrifles.com/accessories/

I also have a Leopold 2x7 scope in Talley QD mounts for longer shots if required.
Longer barrels don't worry me, but I've never been in that dense a vegetation for it to be a problem.

I'm a bit of a tinkerer, so I have a different sighting system (red dot only)for different loads!
Hope this helps
93x64mm