Look into the Godox V350F, V860II, or V1F. I just bought the V1F for off camera shooting, and I'm so happy with the results. I don't shoot professionally, and I use it with a remote trigger on my X-T1
I have an X-T1 as well, and already placed my pre-order for the X100V. I contemplated the X-Pro3, but its too large for the purpose that I would want it for. I think the X100 series is hard to replace if you want something small but mighty. If you want the X100V for the size, the X-Pro3 is noticeably larger even when using it with the 27mm (I had the change to check out a pre-production unit).
Don't forget, the X-T4 is also about to come out, I think I'm going to sell a kidney, and g