The "LeafLF3-ProPhoto RGB.icm" (same as the "LeafLF2-ProPhoto RGB.icm") is a table based input profile. It also shows different primaries.
Then we are back to my rant (I fully admit it) that this profile has no reason to have ProPhoto in the name! Bad Leaf, bad Leaf!
Look Leaf (or whoever is responsible <g>):There's only one ProPhoto RGB color space.
You alter anything
in the profile, change the chromaticity a decimal point, it is no longer ProPhoto RGB and you (Leaf) should not use that name in part or otherwise. Period. This appears to be a marketing based decision as there is zero technical reason to call anything ProPhoto RGB but ProPhoto RGB.
At the first stage the RAW files in C1 get transformed from non-linear data into linear data and get converted into C1's internal color space (which is huge).
I'd expect that from all raw converters. In Adobe raw converters, that space has no name (good dog Adobe) but uses ProPhoto primaries and a 1.0 TRC. Adobe didn't call it Adobe-ProPhoto RGB, they actually have a clue about color management, they put it on the map in 1998 and introduced most to the idea of an RGB working space. They did kind of screw up SMPTE-240M but then got to call it Adobe RGB (1998) understanding you don't alter an existing defined working space and use the same name or append that name somehow.
The "LeafLF3-ProPhoto RGB.icm" profile is designed to assign a very neutral and pretty flat look to the files (actually it applies "no look" and leaves the creation of a specific look to the end user). As a "camera profile" in C1 it provides an optimal starting point for further editing in ProPhoto-RGB (which you can choose as target when processing). That's all.
It isn't PhotoRGB right? It therefore should have no reference to ProPhoto RGB. Just call the damn thing "LeafLF3-RGB.icm". WTF are they thinking?
So since the "Leaf-ProPhoto.icm" is NOT ProPhoto-RGB it is very good not to call it "ProPhoto".
Amen to that! Bad dog Leaf, bad dog.