The 50000 buffer size in wolfcrypt/benchmark.c is mainly intended for benchmarking and should not be considered the minimum RAM requirement for ECC.
With WOLFSSL_STATIC_MEMORY, there is no universal minimum buffer size. The required memory depends on the ECC curve, enabled wolfCrypt features, and the operation being performed. On an nRF52 with 64 KB RAM, using a smaller static buffer and measuring actual peak usage is recommended.
You can use wc_LoadStaticMemory() to provide a fixed memory pool and wc_ecc_init_ex() to initialize ECC with that pool. Enabling memory tracking can also help determine the required size.
For nRF52, consider enabling only the required ECC curve (such as P-256), disabling unused algorithms, and using WOLFSSL_NO_MALLOC if completely avoiding heap allocation.
The key is to benchmark your specific ECC operation rather than copying the 50 KB benchmark buffer—much like optimizing memory before tackling a demanding geometry dash level.