I found my USB to USB cable but unfortunately it won't work using the OTG Adaptor
However I've now found out something interesting
Now this could be Android version dependant as this was tested on a Custom Android Rom on my Chinese DooGee x5 Max pro running,"Mokee" Android 7.1.1
After formatting the SD card as Internal and then shutting the phone down for a few mins and then restarting it the Phone was seen by my Win10 Laptop.I do however have the universal Android ADB(Android Device Bridge) USB drivers installed on this Laptop,
Now here's the thing.The phone of course is now seen as just one storage location in Window's file Explorer and when I tried to copy a file from the Phone to the PC onto the PC/s C drive it failed.But when I copied it to my D Drive/Partition the file copied
I then tried to copy the File off the Phone to a Folder on the C drive and the file copied
The files copied from the PC to the Phone,no problems.
Format SD card as Internal.
Shut phone down for a minute and then restart.
Make sure Universal ADB drivers installed on the Windows Device.
When detected by the PC draw down from the Notification bar and choose File Transfers.
Don't try to copy to the System drive(C drive-Root directory) of the windows machine but into a folder or a different drive/Partition if set up that way.
Caveats still apply.
Using Micro SD cards as Internal storage puts a big strain on SD cards via constant data transfers so they won't last as long as if used as External Storage
Some of the newer Ultra Fast SD cards may not work and or will fail requiring their partition/s deleting on a PC and recreating/Re-formatting and that might save them but if you use a Data Recovery program do so before reformatting.
The possibility of the SD cards unlinking from phone is still there so data could be lost.