Good job on completing the mod, and nice that you got the replacement LCD connector working. But you can clearly see it has already taken a lot of heat. I don't agree with the used technique at all.
Removing the original connector at 350°C is Russian roulette for the game card reader right next to it. The low-melt you have should have been used to remove the original connector. Mix with leaded, then wick, then mix with low-melt. Then you can use e.g. 150°C to remove the connector. Keep in mind that these connectors were soldered in an oven with a lead-free process, so they should be able to withstand 200°C, but certainly not >300°C!
Anyway, no biggie since this connector is thrashed anyway, but if you ever want to remove a good connector from a donor, this is the way.
Then for soldering the new connector.. It is fine to drop some connectors onto molten solder pads like that, but only metal ones like USB or HDMI. Certainly not plastic ones! The process you should follow is to clean the pads, add leaded solder to one of the anchors. Use soldering iron to turn anchor blob liquid, then use tweezers to properly align the connector, then use leaded for all the pins with a precise tip. Done. If possible do it without additional flux (besides what's in the solder wire core), without drag soldering and in 1 go. If using flux, clean properly. Flux gets sticky, don't want that near your connector/cables.
Low-melt solder is NOT to be used for attaching new connectors. It's even more brittle than lead-free and can melt at temps as low as 57°C! Use leaded.