I came up with a quick solution (back in the day man, you had to search for amends without using scripts) which is manually caching the graphics I'll use on that map by putting an event on parallel process, set to transparent and change to every image I'll use, then erase the event as shown here:
Spoiler

When you do that, there won't be any blink anymore because the graphics are already loaded.
Now, I do have a solution, but it's not a practical one. I don't have problems rolling with it tho, honestly, but it'd be cool if any other person out there (or a newbie) that's having the same problem, could get a better, automated solution AKA Plug-in.
I tried Galenmereth's TDD_PreloadManager but for some reason it doesn't resolve the problem. Maybe I'm using it wrong? I did use the custom pre-load command within the .js file, if anyone asks.