As you tried various flashing methods, you might have already known all the related intricasies of flashing. still I just want to mention that I presume you might have then known vcom drivers, creating scatter file with mtkdroid tools, loading scatter file and, most importantly switching off phone and plugging phone to PC just after clicking on flash button in sp flash tool.
And about the other tools of flashing you mentioned, sorry I will not be helpful.
A thing to mention regarding porting is taking care of mount points in fstab file and a similar file if any at /etc folder in ramdisk of decompiled port recovery. mount points should be same as fstab of your boot.img.
Besides, ensure kernel (Imaze) of port recovery is replaced with that of boot.img.
However.. Im not going to miss single chance to upgrade myself ( yes ofcourse from devs n seniors like u)
As you said
1) i have installed vcom drivers & fetched scatter file. ( again not from mtk droid tools) . I heard mtkdroid tools nOt fully supporting mt67xx Series. Even i tried modified mtkdroid tools developed by dev havoc.. And droid tool showed some info like cpu info.. Etc. But right hand side there was an error which saying that its usable to fetch info. . I presume the error may b causing by oppo. Own OS ( Color OS based on android 6.0).. And my last try was 2 months ago. So i dont know if there is any improvements in droid tools or not. Please privide me links if they updated/ supported 67xx series
2)yes i agree with mount points you mentioned. I was just replacing fstab file from stock to. Port. I didnt edit any. . I will check again and update u.
3) Actually im in dilemma to blame on cimpiling or flashing.. The device is not booting even i didn't modify any item after repack. I need solution for that. If that resolved... Automatically everything will b set up by themselves.. Pls share any views regarding this..
I know its difficult to u to guide until u have hands on it or personally seen d procedures & results
I may upload videos / pictures/ share Team viewer etc.. if u want to see it personally.. So.. U can better understand my problem , my flaws where i need to b improved ( onlynif u wish) however i need a mentor to guide n judge methods im following