I dont believe there is such a filter. Due to your told problem with it. Maybe a tiny LC filter to kind of knock the sharp edges off the waveform.
We ran our BLDC dummy load (just R's and L's, through cable with 10 metres between drive (jnverter) and motor.....and all the phones went wrong in the office...so we had to put their phone lines in metal conduit.
Its up to others to sheild themselves from you, not up to you to stop interfering with them....because as you rightly imply, you cannot filter heavily here.