Ive found a solution! Let me just elaborate a guide, but i got shaders and all the optifine features in FTB Rev on my server xD
EDIT:
Ok, its like this and sorry for my English.
Step one: use the vanilla launcher and start a normal game in 1.12.2 using a optifine profile, I've used the 12.2C7
Step two: Configure all the Video options you want to use in the FTB Rev pack, including Shaders!
Step three: Load the resource pack you want
Step four: Quit the game and open The .Minecraft folder (...User/Appdata/Roaming)
Step five: Locate the following files: options.txt, optionsof.txt, optionsshaders.txt.
Step six: Locate FTB Rev folder (...docs/Minecraft Curse/Instances/FTB Revalation) and make a secure copy of the following files, if present: options.txt, optionsof.txt, optionsshaders.txt
Step seven: Copy all the three files to the FTB Rev folder and replace the files there
Step eight: Copy or place the Resource packs or Shader Pack (in the case of the shaders make sure you copy the options.TXT from the chosen shaderspack) to the correct folder in FTB Rev.
Step nine: Make sure you have enough memory, Personally ive to increse from 6 to 8, Im using Spha 64x and SEUS Reneweed shaders.
Step ten: Launch FTB Rev and when loaded, NEVER OPEN THE VIDEO OPTIONS, you can enter any world (tested single with several worlds and online on my own server)
Step eleven: Share love not hate and happy new year!
"Proof":
https://imgur.com/FFgSeLk
