Follow-up to support post
After having a rather poor experience with the Microchip online support systems (see this post) I finally made contact with a US-based support engineer and in a matter of a couple of days he resolved the issues I was having.
Basically he suggested trying a different driver framework for interface to the WINC1500 module. That driver for the WINC1500 is part of the Microchip Libraries for Applications package. After implementing the new SPI and set up methods the breadboard setup of the evaluation WINC1500 module is looking like it is working.
The next step requires the updated PCB in order to test the wireless functionality and once that is achieved I will be posting the full solution so that others who need to interface between the WINC1500 module and an STM32 device don’t have similar issues … watch this space.