Something else to take into consideration is that some tracers should
be thinner than others. I was testing the Il2 Type 3M, the
plane that has 2 7.62 guns and 2 37 cannon, and the tracer
cavity diameter for the 37mm should be much larger than that of the 7.62x54R cartridge when rendered in game.
What this means is the tracer for the 7.62 should appear much thinner but being
the same length. Shooting both gun types simultaneously and seeing the tracers
as the same diameter just isn't right

Tracers for 7.62 (30 caliber) weapons should be thinner than those for 50 cal,
20mm, etc. To be clear, the tracer diameter is NOT the same diameter as the
projectile. Some tracers on the larger calibers were a simple threaded cup that
could be screwed onto the base of a projectile while others were designed into
the projectile itself. I have a small collection of WW2 aircraft ammunition,
including a rare BK3,7 Hartkern.
I know you're all about accuracy and this is another huge step in the historical direction!
I have a rare book on the Flying Guns of WW2 (and WW1 as well) with many diagrams
and blueprints of the different projectiles used by all sides.
As an example, a 30 cal 7.62mm tracer generally has a tracer diameter of about 5mm.
A 50 cal (12.7mm) tracer is about 8mm (for a boattail) and a 20mm tracer has a cavity 10-15mm depending
on type. Once you get to larger calibers than that, the tracer diameter is generally
between 10 and 15mm, regardless of projectile size.
Regarding the "squiggle", that's something that only a camera records when it's shook or vibrated by the guns firing. Human eyes don't see them that way. Perhaps make an option to switch between straight for cockpit or free cam views, and squiggly for gun cam videos edits.
How about a texel that shows the squiggles ONLY while a gun button is pressed! THAT would be pretty good!