proportioning/metering/distribution valve clarification

Well my 66 Barracuda originally 9" drums... now 10" drums will be getting an almost complete 68 KH front disks as well as a 69 8-3/4.

The question of the correct or at least options of:
Early distribution block(BLK245 Inline) with the separate Rear proportion valve(pr104b- Inline Tube) ,
Or a combination 69-74 distribution block with the rear line restriction built in(BLK250- Inline) ,
Or the combo valve with the front line metering valve attached to the side sold on Ebay as MBM-PV6070MOP-Mopar 1960-70 Disc Drum Proportioning Valve (that I already bought).

I do understand that there is some debate on this mater.
Is the metering valve for the front lines required with the 68 KH set up? Why would a pressure restriction to the rear line AND a metering " delay" to the front be used at the same time? Seams like a slow progression of engineering "corrections".

I read through many conflicting posts and threads with pieces of info and opinions. My thoughts today with the info I have gleaned... I could remove the metering valve....