i havent been able to successfully use the slime block method but i have found a consistant way to use the water method. you go down by 17 blocks and across by 11 blocks measured from the closest portal frame, all in downwards flowing water. The water having a one block gap of air between it and the portal. You have to stand on a wall point straight upwards with speed 1 and depth strider 3. start sprinting then almost instantly (whilst still holding sprint) hold jump. you should end up just between the last portal and the frame. you should then be teleported to the overworld coords in the end. if you get the timing right you can get it to be 75% accurate or so.
i havent been able to successfully use the slime block method but i have found a consistant way to use the water method. you go down by 17 blocks and across by 11 blocks measured from the closest portal frame, all in downwards flowing water. The water having a one block gap of air between it and the portal. You have to stand on a wall point straight upwards with speed 1 and depth strider 3. start sprinting then almost instantly (whilst still holding sprint) hold jump. you should end up just between the last portal and the frame. you should then be teleported to the overworld coords in the end. if you get the timing right you can get it to be 75% accurate or so.