OpenCV Seam Finder problem with a lot of images. How to properly use tiles?

I'm using OpenCV 3.4.8 in the C++ code. I have over 1200 images, where one i around 100-200 MB size. I know their positions on the final image. Images partly overlapping, sometimes they are quite dense.

I need to detect the seam lines and finaly merge it to the one image. I'm using DpSeamFinder. Because there are a lot of images and thier size is big I can't load all to the memory. I've tried even with thumbnails with only 10% of the size, but the functions crashes.

Now I'm trying to divide the final image to the regions (tiles) and load all images that intersect with curent tile and as a final step just merge tiles to the one image. It works pretty good, there are no crashes etc, but there is a problem with detected seam. Sometimes there are huge difference in the seams beetween two tiles. There is some way to improve the seam finding using tiles to achive my goal?