Here’s the issue. No neutral. Actually there is a neutral but only intermittently as they miswired theb fxyure so the neutral comes over the 3 way travler wire.
My initial.solution was smart bulbs and tape the swith on. But people kept turning it off like cleaning lady and or loose control.of the bulbs. I Didnt want to hard wire both switches as then there is no manual control at all.
New fix was the following smart switch which actually turns on/off the underlying switch and a rule to then it back on after it is turned off and also reset/turn off the smrt bulbs as those turn on when power is reapplied. See attachments. I use my own copy of rule machine (just my prefernece) but you get the idea!