APC PDU HTTPS wildcard certificate

[SnowflakeComputing]

All of my PDU's and UPS's are using a self signed certificate currently.  I would like to replace this with a certificate signed by my internal CA.  I already have a wildcard certificate that is signed and has been uploaded to numerous other network devices, so would like to use this same certificate.

I am focusing specifically right now on an AP8641 PDU with the following NMC running rpdu2g 6.9.6:

Network Management Card

---------------

Model Number: AP9538

Serial Number: [snip]

Hardware Revision: 05

Manufacture Date: 08/11/2021

I am unable to upload the certificate in its current format - .p12.  I have converted it to a .pem file and tried that, but it also does not work. 

After reviewing the forum threads here, there was suggestion to use the graphical UI tool "APC Security Wizard v1.4", which I have looked at (as well as the CLI tool).  It appears that I need both a signed certificate and a PKCS15 keyfile in order to import to the tool.  I do not have a .p15 file, nor is there any easy way to generate one.  Openssl does not seem to have a method to convert keyfiles to .p15 format.  Oddly enough, APC is the only vendor I have ever come across that requires a .p15 formatted certificate.  Searching the internet shows that I'm not the only one to find this extremely odd and a one-off.

I tried using the CLI tool as well, but it complains about not having a .p15 formatted file.  I'm essentially blocked at this point.

My question for the APC/SE community is:

Is it impossible to use certificates that are not generated by the APC Security Wizard or CLI tool?