The Transformational Power of Frequency Phase Transfer Methods for ngEHT

(Sub) mm VLBI observations are strongly hindered by limited sensitivity, with the fast tropospheric fluctuations being dominant culprit. We predict great benefits from applying next-generation frequency phase transfer calibration techniques for next generation Event Horizon Telescope, using simultaneous multi-frequency observations. present comparative simulation studies to characterise its performance, optimum configurations, and highlight of including at 85\,GHz along 230 340\,GHz bands. The results show a transformational impact on ngEHT array capabilities, orders magnitude improved routinely possible over whole year, ability carry out micro-arcsecond astrometry measurements highest frequencies, amongst others. This will enable addressing host innovative open scientific questions in astrophysics. solution highly scatter-broadened sources such as SgrA*, prime target. conclude that adding band provides pathway an robust performance sub-millimeter VLBI, recommmend inclusion receiver design.