AGFA considers 0.65 to be the normal contrast index. HP5+ will not reach that CI in Rodinal 1+50. Their table for HP5+ in Rodinal 1+100 specifies reduced CI.
Most of us consider 0.65 to be on the high side of normal, especially those who use condenser enlargers.
I have found the maximum CI of HP5+ in Rodinal 1+50 to be about 0.61. If you try to go beyond that, you get more base fog.