Your test is reliably dropping frames here and there. You said yourself it drops a frame every 10 seconds or so.
I can have DOOM (with a Chrome, skype, c2 editor, discord, screen recorder all running in the bg) drop less frames than your test on the same machine.
Any fluctuation caused by OS processes causes more issues with the test than it does in DOOM.
I understand the major performance problems people are experiencing can be traced down to a number of OS/Browser issues, but even at it's best, a simple test cannot outperform a modern 3D shooter.
People having bad code is also a different issue entirely. Some of the commenters here might have a problem related to that. I understand that there's a mix of issues blamed on Construct, some are legit, some are not. Everyone should heed the repeated advice of sending over minimal reproducable cases that can isolate the causes and those can be forwarded to directions where they're helpful.
There's also been first hand experiences with larger games where writing messy code will result in less performance drop in Unity.
As for the next penelope, there was a post-mortem (which I have saved, which has been deleted on the internet) pinning abysmal performance on WiiU (advertised platform) on HTML5 and "gifted" helpers couldn't do much resulting in the attempt to rewrite the whole game in C++.
Could you please comment on each of these Ashley
1) It is impossible to have a C3 app not drop frames on a minimal project on each of the advertised platforms.
2) Vsync cannot be disabled, thus you're stuck with lag associated with Vsync.
3) These issues are out of your hands because of HTML5.
Your confidence in your engine is well founded, I certainly believe you when you say "it's working great". It is an amazing editor and gives me the ability to work at a speed I've never experienced before. Your work is spotless and the editor is robust.
The way I see it, HTML5 is the best solution for Construct currently due to your small team, but it comes with an epic boatload of small issues.
Each device build is tangled on other vendor's problems like a hellish hair day.
You've said native comes with it's own baggage with graphics driver changes and such, but the vendors handling these changes are "gamers first" people. See for example Nvidia G-Sync, which allows the screen to draw instantly when the frame is served. Awesome stuff.
The solutions I see here are either to bug the hell out of the device and browser vendors and wait for everything to sort out (which has been going on, but I saw peak performance of HTML5 7 years ago when a super talented team made a competing engine to Construct and the only advance since has been improvement in audio playback. Some things have even gotten worse.)
Get a bigger team and do native. It's a hurdle, but at least here it's possible to reach "perfect" performance.
Out of curiosity, how many labor years would it require to get a native exporter?