I have a couple of really old servers and mine on official pool "pool.lbtc.info" on 6343 port. But stratum difficulty, which is 1, is very high for those servers and I constantly get the message "stratum_recv_line failed".

Is it possible to have additional ports here with lower difficulty (0.5 or even 0.1)?

URL (difficulty 0.1):  stratum+tcp://pool.rplant.xyz:3355
URL (difficulty 0.5):  stratum+tcp://pool.rplant.xyz:3356