You will find this helpful. I have a Freud alignment plate from the way-back machine. A blade is pretty true but, a dedicated plate will show you just how variable different blades can be. regardless of the arbor mounted assistant of choice, rotate the plate or blade to check against the same spot front and rear . . .
OK, now I'm just repeating what you already know . Sorry about that, must be the coffee.
As C Shaffer said; longer reference plane. Be sure to avoid the pitfall I read so many mention; use the miter slot you will run your miter gauge in as the reference slot. Generally this is the left slot but, many folks will post for help after aligning to one slot and then using the other to actually make their cuts. Test with "A" then use "B"? Not.
One would like to think that machining reasonably parallel miter slots in a tablesaw top would be child's play in our modern age. However, it seems to escape even the name-brand tablesaw manufacturers in some models.
With the blade aligned to the slot and the fence aligned to the same slot you can get very close pretty quickly. Once you are good at 90* you will have to consider bevel angles.
With cabinet mounted trunnions, getting a good alignment at 90* and at 45* is straightforward. You will love this after struggling with a table-mounted trunnion design.
Once aligned at 90* if the alignment is not true at 45* (usually not) you simply alter the plane of the table to blade relationship. this is done by shimming the front or rear of the table as required.
Shim stock is available but, I have had good success with hole-punched squares of cut up aluminum can that set on the bolts like washers. A shim as added at both rear mounting points or both front mounting points as required to bring the table into plane at bevel angles.
I adjust at 90* and at 45* and satisfy myself that the angles in between are now as good as the machine will allow. that is; I don't kill myself at 22.5* if it is not perfect.
I will say that time invested now in a good alignments will save you time and material (not to mention frustration) for years to come. Enjoy your new saw ;-)
P.s. this was helpful to me as well . . .