Well, in fanfiction, anything can happen, so Harry can definitely use the Force. This would be really interesting as it would mix two very different fictional universes. It might make Harry a more complex and powerful character. He could use the Force to levitate objects in a different way than he does with magic, or he could use it to communicate with other Force - sensitive beings, creating new alliances and story arcs that we would never see in the original Harry Potter series.
Sure. Fanfiction is a realm of limitless creativity. Harry using the Force could open up many storylines. Maybe he discovers he has this ability through some sort of magical - Force - related accident. It could change the power dynamics in his battles against Voldemort. Instead of just relying on spells, he could use the Force to deflect dark magic or even foresee Voldemort's moves in a more intuitive way.
A practical answer is Chapter 1, because it turns the idea into a concrete scene. The chapter opens with Jiang Li, I'm warning you, don't set your sights on Yinwan anymore, or..., adds pressure through Coming to his senses, he also switched to a kindly smile, "Alright, girl,..., and ends on Yet.
Chapter 499, "Jiang, the Malicious Merchant is Online Again", is the clearest early answer because it turns Shang Shuyue's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Jiang Cheng: "...." "And another thing," Jiang Yan stroked his chin...
Chapter 591, "Is There a Way to Get to the Bottom of the Lake?", is the clearest early answer because it turns Feng Shui's situation into a concrete plot event. The chapter turns that into something concrete by moving from But my focus isn't that," Jiang Li's tone shifted, "What exactly is...
Chapter 387, "Hello everyone, this is my disciple", is the clearest early answer because a shaky connection becomes usable in the plot. A useful checkpoint is the way the scene starts with Liu Suqing V: "Even if we meet, I wouldn't recognize, faces covered...
Chapter 606, "Are There Crocodiles?!", is the clearest early answer because it turns Mouse Game's situation into a concrete plot event. Early on, Hearing Ji Yanbai volunteer to stay behind, everyone ceased to have....
Chapter 563, "Quite the Confidence", is the clearest early answer because it turns Quite's situation into a concrete plot event.
Chapter 799, "You Bad Woman!", is the clearest early answer because it turns Jiang Bufan's situation into a concrete plot event. Early on, Jiang Yan irritably covered one ear and complained to Jiang Li, "Why.... By the end, The temperature was just right, and the fresh scent of lemon....
Chapter 582, "Fleeing Hastily", is the clearest early answer because it turns Chen Manman's situation into a concrete plot event. The chapter turns that into something concrete by moving from Luo Xuan pushed her away, disappointment filling his eyes.
Chapter 684, "It doesn't matter if it gets broken, I have the money to fix it.", is the clearest early answer because it turns Mr's situation into a concrete plot event. The setup is But Jiang Li had already evolved;
Chapter 440, "You Know Fengshui Array?!", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event.