I'm replacing the cables and housing on an old (80s?) Fuji Regis road bike that I'm fixing up. The front derailleur is a Shimano FD-AX50, which has a somewhat strange flat cable stop built into it, and the down tube has Suntour cable stops bolted on, with one of those curved cable guides on the right side for the rear derailleur cable. The issue that I'm having is that the left down tube cable stop forces the housing to take a fairly sharp angle up from the bottom bracket to get to the cable stop on the derailleur. Putting aside my concerns re: excess wear from the sharp turn, this angle prevents the ferrule on the housing from staying straight, so the cable rubs against the hole in the cable stop. Am I missing something? Is there a better way to route this? Do I need a different kind of ferrule? I've tried playing around with different housing angles and bends for quite a while, but I'm stumped.

Here's a photo of how I currently have the cable routed.