Okay, I'm back, having read all of the arguments, and I still think Regulus wins.
Based on what I've read, while Tatsumaki's starting attacks may be large-scale and reckless, she does not begin with instantaneous BFR into space or into a place where Regulus would hypothetically lose connection with his wives. It's possible for her first move to be that, but typically she will attempt to crush her opponents or uproot massive expanses of land to attack them, and given Regulus is just one guy, I see no reason for her to decide to uproot land when she can just use her TK to crush him or use smaller masses to end hi, at least initially.
The way I see this fight going down is Tatsumaki realizes Regulus is a spatial distortion and tries to do what she usually does and crush him. Her initial attempts don't work, and not yet realizing Regulus is invulnerable, she will attempt continuously larger scale attacks until Regulus simply decides to ignore her telekinesis all-together, making him unmovable. Then, all Regulus needs to do is flick, and she's dead.
It's not a stomp, in my opinion. But the world in which Tatsumaki instantly deduces that he's invulnerable and begins with her largest scale attacks (which would kill his wives, of course) or simply decides to throw him off the planet seem exceedingly unlikely to happen with her standard mindset, and all Regulus has to do to invalidate these wincons is for her to direct any of her standard attacks at him and then decide he doesn't want her abilities to move him anymore, which doesn't require any extra focus on his part, giving him leeway to basically do whatever he wants.
Not a stomp by any means, but Regulus will still probably win.