pretty much I dont know a lot about older machines, as I use a new Consew and Adler. Alot of trimmers feel that it is easier to use a single needle machine due to making compound curves on double needle machine is a complete pain in the As*. single needle will never bee as straight as dual but can be damn close, dependant on the trimmers skill set
Attached is a needle guide for leather that was made available By greg at Keystone sewing in philly, great guy!! should remedy the same on alacantara.
I was curious if you had ever had a seat in alacantara before, simply because a bit different, not a huge fan of it and that stuff is anything but cheap.
Keystone bros has a similar material known as street suede, and personally, 12 bucks a yard sounds great compared to 70 bucks a yard lol.