Asus Strix Z370-E with i7-8700k: would Bios WITHOUT Spectre (and meltdown) microcode update be to an UNPATCHED windows7 64 OS performance?

I bought this board specifically to avoid the Spectre and Meltdown microcode Bios updates as I intended to use it in dual boot windows 10 Pro and Windows 7 Ultimate 64bit. It had Bios 0428 which I thought is the original Bios, but inspectre tool revealed that hardware mitigation (CPU microcode patch) is present:

- Does the presence of the hardware CPU microcode patch for spectre/meltdown impact the performance even of an UNPATCHED windows 7 OS?
- Is newer intel motherboard firmware necessarly " bad" for windows 7?
- Is having latest Bios and latest Intel firmware possible with microcode free of spectre-meltdown patch?

Thanks in advance for your help.