(Note: in the EPSG dataset, Gauss-Kruger and Gauss-Boaga projections are considered to be the same than Transverse Mercator.)
We could port most of the Transverse Mercator projection in Geotk (after IP review), but the formulas changed. The formulas used by Geotk were derived from USGS, while the formulas used by EPSG (called "JHS") are accurate over a wider range of longitudes.
Consequently, we should rewrite the Transverse Mercator projection from the new EPSG formulas.
See §184.108.40.206 in IOGP Publication 373-7-2 – Geomatics Guidance Note number 7, part 2 – April 2015.