[NTG-context] Taking extensible math accents from fallback font

Hi, Is it possible to take particular math accents from the fallback font. In praticular, I want to use NeoEuler as the math font, but want the \widehat and \widetilde accents to be taken from Pagella. This is because the widetilde accent of neo euler does not change the the size of the glyph. Until that is fixed, using the accent from another font is a stopgap solution. Thanks, Aditya