For people still playing this that have issues with there proper minecraft skin loading, i think i managed to pin-point this old bug\glitch.
I was carefully going over the mod configs to try and pinpoint the issue (from a lot a redit and forum comments you could make up that in some cases the skin shows (multiplayer some times even sync shells on singleplayer)), i was quite sure it was a client side thing hence the reason why i started looking into the configs when updating random suggested mods dint do the trick for me.
I found the following line of code in "Openblocks.cfg" lines 279/280 under the "hacks" section:
Code:
# Allow OpenBlocks to hook the player renderer to apply special effects
B:tryHookPlayerRenderer=true
I am not quite sure what it does, and why it exists (i dint do my research on the mods wiki), but when i reloaded my client after swapping it to false, my character once again showed up with the proper skin loaded that i uploaded to mojang.
I did a quick google to see if there where any solutions to be found, dint find any solid confirmed once, if this helps feel free to post here that it works, i doubt the pack will still receive updates for it to become a default config.
Cheers