I have written a freeware command line utility, that can be used in a batch file called by the advanced export section, that renames (copies) the exported files to .php extensions and renames all internal .html references to .php
This is being tested on Windows 32/64 bit and Ubuntu based Linux 18 (32 bit) & 20 (64 bit).
There are plans to add additional features, such as simple php code checking and others.
If you would like a copy and help me test and develop this utility (especially on other versions of Linux) please reply to this topic or email me directly.
Regards from down under