That does not decrease the importance of these trains in any way. Besides, these trains parking time at SBC is a relatively free time for SBC with not too much traffic. 17236 departs within 2 hours of arriving at SBC as 17209 and arrives long after all the early morning arrivals reach SBC. That way I don't think there is any obstruction of PFs by these trains. Also, 17209 arrives mostly on PF2 or PF4 while MYS bound trains have to start from PF5 onward ( 1,2,3,4 PFs are not accessible to MYS line). So in all probability, they are not posing any obstruction to introducing a MYS bound train in the evening.