This repository is more or less archived.
If you need support or customization for existing projects, it is still available (please contact info at ifcquery.com)
For new projects, I recommend xeoIFC (https://github.com/xeofoundry/xeoIfc)
It is much more recent, the geometry quality and robustness is much better, CSG operations are more stable, and it can run also in WASM.
XeoIFC has a very low memory footprint and very high performance.