The rip chains will help a lot, for several reasons. First, the angle is normally 0-5 degrees, which is better for rip cuts that produce sawdust instead of chips. And many rip chains are setup with asymmetric cutter shapes so that the cutters work in tandem, doing a right, then left, then center cut to clear the kerf. Much easier on the saw than a single cutter clearing the whole kerf. You can certainly re-grind the angle on a regular chain to 0-5 degrees (good way to use up a spent firewood chain) but it would be harder to grind the cutters asymmetrically.
The downside to rip chains is that they are difficult and unsafe to use freehand, and you really need the saw mounted in a jig to be safe and make a nice cut. Otherwise they will wander and kick. I have an Alaskan rig made for ripping beams, and it was only about $80. It comes with guide rail that you can screw to an LVL or glue-lam beam to be your reference edge. Screw that board to the log, and then the saw bar dangles over the edge and makes a cut 90 degrees to the board. Keep rotating and repeat if you want all 4 sides squared, otherwise you can just stop with that first edge if it's enough.
The Alaskan rigs made for ripping boards are more expensive and clunkier to use, usually $200-300 or more. For that, I still make the first cut with the beam jig to get a nice flat starting surface.