Meaning of CRT Range values and defining modelines in Arcade OSD

[BigBoss1964]

Hi dears

First of all a million thanks to Calamity et. al. for the brilliant CRT Emudriver. Its a dream come true.   

I wanted to ask the meaning of some of the parameters in CRT Range. i.e. what difference to the geometry they make. I know a couple but not the rest.

crt_range0

HfreqMin-HfreqMax, VfreqMin-VfreqMax, HFP, HSP, HBP, VFP, VSP, VBP, HPol, VPol, PLMin, PLMax, ILMin, ILMax

HFP -- horizontal front porch   

HSP -- horizontal sync pulse

HBP -- horizontal back porch    (I believe used to move the screen horizontally)

VFP -- vertical front porch

VSP -- vertical sync pulse

VBP -- vertical back porch       (I believe used to move screen vertically)

HPol -- horizontal sync. polarity

VPol -- vertical sync. polarity

Can you guys please let me know what these other values do in terms of geometry. Is there any option to "shrink" or "expand" the screen vertically or horizontally or the whole displayed area/frame.

Secondly, is there a way to add modelines to arcade OSD without having to generate/install them through VMM. As this overwrites all the fine geometry adjustments I have made for modelines in Arcade OSD.   
I can usually add a resolution to "user - super resolutions.ini" but Arcade OSD doesn't see it unless I use the "install modes" function in VMM.

Many thanks in advance!