As of now it is clear to us that the best way to go about making games with Construct is to keep them small (due to browser memory limits which we are dealing with sadly. Engine crashes very often (out of memory error) because of how large the project is
As far as I'm aware browsers, and Construct, don't have any particular memory limits that would affect even a large game. For example you can use as much texture memory on the GPU as you can - there's no limit there. No matter what software or technology you use, it's up to you to design your game efficiently and not use too much memory.
Temp file creation is also an unexpected issue with games made with Construct. Players have reported over 10gigs of temp files get created over a 20 hour total play session.
Construct doesn't itself try to create any temporary files, and that sounds like some kind of fault. I think it's possible it's also a bug in your project, e.g. if it has a storage leak - hard to say without a bug report.
There is also the issue of the games running on NWjs so devices with dual graphics card often offload NWjs games to the onboard card
Yeah, that's been a long-standing problem, but it's difficult to do anything about - the graphics card vendors have system-level software that overrides what the app asks for. You could try contacting them to change the default for your game. I think people found some workarounds, but they don't seem to be well documented. AFAIK this affects all indie games in general - if you publish a game that isn't big enough for the graphics card vendors to know about, then their system software often defaults it to the low-power GPU, regardless of what the app asks for (if your project property 'GPU preference' is 'High performance', which is the default, then Construct is asking for the better GPU on dual GPU systems, but the system may ignore that request).