While some choose to use a high pass filter to the main speakers with sub(s), I think there are many reasons to not. A lot of popularity with high pass filters comes from AVR surround sound, where there are Dolby settings in the AVR processor for this. the theory is that it cleans up signal going to small main and certainly small surround speakers.
But for great stereo imaging, and disappearing subs, getting the most bass cues possible to your left and right speakers helps immensely. Your ear can localize tones quite low, so using the low pass filter on the sub prevents you from localizing these sounds. Think plucking of the bass string vs the deepest tone it creates.
As @avanti1960 said, you have respectable bass output with your speakers, use it. This allows the lowest possible cut off for your sub.
Additionally, adding any filter, processor etc in line with your speakers potentially inserts distortion. I work very hard to avoid this. No room correction, Roon processing, graphic equalizer etc.
I am not knocking quality high pass filters. But at best they add complexity. I have enough wires!
the only reason I would consider not sending full signal to my mains is if the woofers were flopping or distorting. And most quality speakers with good amplification do not do this.