missing GeomCAL functionality in BricsCAD?

If you are missing AutoCAD's GeomCAL functionality in BricsCAD then there is a solution: just download the freely available CADCAL+CALScript from https://www.calscript.com/home.html

CADCAL is a full replacement for GeomCAL, with even enhanced functionality. Most interesting is probably the dialog driven DDCAL command: DDCAL. You don't need to remember the syntax of CAL functions, but can simply select the desired function from a listbox. And DDCAL saves all math expressions and the results in a history, so you can easily access these functions and their results even after closing and reopening the DWG file.

And have a look at the CALScript part of CADCAL & CALScript. This is a completely new approach to parametric design. In many ways it's like dynamic blocks, put it is much easier to handle and much more powerful.