High latitude terrain correction with a lambert/conical projection

I am currently working with SAR GRD data for Northern Iceland. My data analysis is highly sensitive to elevation, so I’ve been using an external DEM (high resolution EPSG:8088, lambert conical projection) reprojected to WGS84. However, re-projecting introduces significant inaccuracies (>10m) in many of the areas I am looking at. I would love, if possible to do radiometric terrain correction without having to re-project my DEM (or next best case, with the ability to use UTM27).

Does anyone have any experience with python scripts for terrain correction that integrate well into the snappy pipeline (that have more latitude in input DEM projections)? Any other workarounds would also be appreciated.

Thank you!