I did mention it briefly in the post, but you can opt-in for a fixed-size statically allocated buffer by configuring libstdc++ with --enable-libstdcxx-static-eh-pool. Also, you can opt-out of the pool entirely by configuring the number of objects in the pool to zero with the environment variable GLIBCXX_TUNABLES=glibcxx.eh_pool.obj_count=0.
The exact implementation of mymalloc isn't relevant to the post. I have an old allocator published at https://github.com/joelsiks/jsmalloc that I did as part of my Master's thesis, which uses a similar debug-logging mechanism that is described in the post.