The Samsung Galaxy S8+ model SM-G955V is distributed by the US carrier Verizon. Experience shows that this carrier locks the bootloader irrevocably, so that no change of the StockROM Android is possible. Additionally, the US model SM-G955V is equipped with a CPU Qualcomm Snapdragon.
The /e/ OS ROM currently only supports 2 European models SM-G955F/FD with Samsung Exynos CPU.
For the Samsung S8+ “dream2lte” the migration to /e/ OS 9-Pie is on the way.