I request a technical discussion.....

regarding a cans performance, would it make a difference if a can had a brake as the mounting point, or rather incorporating a 'blast baffle' in the design?

Yes, I know that all cans have a blast baffle, specifically the first baffle in the stack.

But for an intellectual exercise, let us consider 3 cans, all the same overall length.
Can number 1 is made up of a total of 6 baffles, all of them 60* cones. It has a taper mount and mounts onto a brake on the barrel which extends into the blast chamber.

Can number 2 also has 6 baffles of 60*. It is a direct thread onto the rifle barrel, but just in front of the muzzle is a flat 'blast baffle" that is ported to allow expansion from the muzzle to the first cone baffle.

Can number 3 is a direct thread mount. But it has 7, 60* cone baffles in front of the muzzle with the first cone acting as the 'blast baffle'.

My question is what will be the differences in performance between the cans? I ask this because it has been discussed that a brake mount aids in performance. I just wonder if a direct thread with additional baffle will aid in a similar manner and amount.

Hmm. well I think it goes without saying that a brake adds a second benefit as it acts as a sacrificial baffle that is replaceable.

Here's my take on the subject.

Can #1 would be the most versatile. Reasons being 1 the sacrificial baffle aspect, 2. you could modify your brakes to act differently (example. on my 30 cal can I plan to run 3 different types of brakes. 1. a traditional brake where the mounting is roughly equal to the muzzle threads but have larger ports or multiple ports, 2. a Over The Barrel (OTB) brake. where the mounting is behind the muzzle threads, 3. a minimalist brake or virtually direct thread ie. 1/4" brake opening directly after the muzzle.) by doing so I can in essence tailor the blast chamber volume by how much the brakes displace internally (OTB is 5.56, standard .308 and .260, minimalist 300WM)

Can#2 The main benefit I could see with this one is potentially less FRP and the spacer could be made thicker and stronger to aid in durability

Can#3 This is really going to come down to cartridge and length. if it shrinks the Blast chamber down to much for the intended cartridge the blast baffle is going to hate life, backpressure would likely be higher on gas operated weapons, suppression may or may not benefit from the added baffle.

Can 1 less volume in first chamber due to muzzle brake.
Can 2 you still have a blast baffle you just cant change it, and probably won’t work any better then another cone.
Can 3 more baffles of good design = less noise.

Muzzle brake adds sacrificial brake and helps mitigate POI shift without suppressor attached if weapon will be shot without suppressor.

Cartridge and use factors drive the over all design.

IE Subsonic vs Supersonic, carrying weapon vs rest/tripod shooting.