Magpies are so sneaky! My magpies used to try that but they didn’t get much of a chance once a seagull would swop down to take over.
I made a plastic box that I use as a feeder (with tube at the entrance) it took about a month for te hedgehogs to get used to it. I would scatter a bit in the tube or in front of the box.
I’m glad a kept trying with the box as the cats/magpies/fox/ don’t get it and it slows the wood mice down.
I’d love to leave food scattered around but in my garden it doesn’t really work. Funny thing now…if I ever do leave a dish of food outside the feeder so that I can watch from the kitchen they walk straight past it and head ino the feeder.
I think if I was in your situation I’d use a small amount in your feeder. Might be tempted to leave a bit of food outside the feeder but would probably do that in a weeks time. (To put the magpies off)
This is just a thought though. Every garden is so different good luck 🙂