Samsung Galaxy K Zoom (samsung-m2alte)

How to enter flash mode (download mode)
Hold +  +. Press when prompted.

Alternatively, try.

Enable USB Debugging

 * 1) Open Settings > About device
 * 2) Tap Build number 7 times
 * 3) Return to Settings > Developer options (newly appeared!)
 * 4) Enable USB debugging

MUIC
According to the modified downstream kernel (kzoom-katkernel config), this device has a Maxim Integrated MAX77803 MUIC. According to the Micro-USB_Interface_Controller page, this is the same MUIC as in the Samsung_Galaxy_Note_3_(samsung-hlte). I also found driver code for this MUIC in LineageOS/android_kernel_samsung_exynos5410