Here is a complete program fixing the issue on both kind of devices. You can pass extra hid devices, it'll apply only to known ones. So you can simply call it as ./a.out /dev/hidraw*

#include <linux/hidraw.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

int main(int argc, char **argv) {
  printf("Pass all devices to configure. For example, like this: %s /dev/hidraw*\n", argv[0]);
  int expected_desc_size;
  char data_to_set;
  for (int argnum=1;argnum<argc;argnum++) {
    printf("Trying to configure %s...\n", argv[argnum]);
    
    int fd, i, res, desc_size = 0;
    char buf[256];
    struct hidraw_devinfo info;
    char *device = argv[argnum];
    fd = open(device, O_RDWR | O_NONBLOCK);
    if (fd < 0) {
      perror("Unable to open device");
      return 1;
    }
    memset(&info, 0, sizeof(info));
    memset(buf, 0, sizeof(buf));
    
    // Get Raw Info
    res = ioctl(fd, HIDIOCGRAWINFO, &info);
    if (res < 0) {
      perror("HIDIOCGRAWINFO");
      return 1;
    }
    if (info.vendor == 0x05ac) {
      printf("Apple device found!\n");
    } else {
      printf("Not an apple device.\n");
      continue;
    }
    if (info.product == 0x022d) {
      printf("We have a 'magic' keyboard\n");
      expected_desc_size = 218;
      data_to_set = 1;
    } else if (info.product == 0x0250) {
      printf("We have an 'aluminium' keyboard\n");
      expected_desc_size = 75;
      data_to_set = 0;
    }
    else {
      printf("Warning: Unknown product ID 0x%x!\n", info.product);
      continue;
    }
    // Get Report Descriptor Size
    res = ioctl(fd, HIDIOCGRDESCSIZE, &desc_size);
    if (res < 0) {
      perror("HIDIOCGRDESCSIZE");
      return 1;
    }
    if (desc_size != expected_desc_size) {
      printf("Error: unexpected descriptor size %d; panic'ing", desc_size);
      return 1;
    }
    // Get Feature
    buf[0] = 0x09;  // Report Number
    res = ioctl(fd, HIDIOCGFEATURE(256), buf);
    if (res < 0) {
      perror("HIDIOCGFEATURE");
    } else {
      printf("HID Feature Report (before change):\n\t");
      for (i = 0; i < res; i++) printf("%hhx ", buf[i]);
      puts("\n");
    }
      
    // Set Feature
    buf[0] = 0x09;  // Report Number
    buf[1] = data_to_set;  // Report data
    buf[2] = 0x00;  // padding
    buf[3] = 0x00;  // padding
    res = ioctl(fd, HIDIOCSFEATURE(4), buf);
    if (res < 0) {
      perror("HIDIOCSFEATURE");
    } else {
      printf("Caps lock delay disabled.\n");
    }
    // Get Feature
    buf[0] = 0x09;  // Report Number
    res = ioctl(fd, HIDIOCGFEATURE(256), buf);
    if (res < 0) {
      perror("HIDIOCGFEATURE");
      return 1;
    } 
    printf("HID Feature Report (after change):\n\t");
    for (i = 0; i < res; i++) printf("%hhx ", buf[i]);
    puts("\n");
    close(fd);
    }
  return 0;
}