I submitted 3 tickets for crashing QtWebEngine when using Falkon. Maybe someone can fix these issues and get those websites working?
The above benchmark websites work with Webpositive but crash QtWebEngine when running on Falkon.
Fixing these bugs will either improve or fix QtWebEngine stability. Thanks.
3rd ticket below:
Welcome, gandalf!
Filing tickets is a first step to fixing bugs. However, it doesn’t take much to crash Falkon… 
Falcon is not recommended to use!
Use Web+ instead!
EDIT: For some sites Falcon is the better choice, for some!
I use Web+ for 99% of my browsing needs. I just have Falkon around for the sites (or some functions of a site) that don’t work. For example, closing issues at github or editing the user guide so I don’t get logged out the first time I want to save a change.
It’s good to have a fallback in such situations, but generally I do prefer WebPositive.
Thanks humdinger. I blinked and Falkon crashed on me. 
Fixing QtWebEngine crashes would make Falkon run stable and work better. It should not crash QtWebEngine running those online benchmarks. Webpositive can finish all the online benchmarks except for JetStream2. Likely missing support for WebAssembly? Or something else?
Whether QtWebEngine gets fixed or not we will see. There is also Epiphany with Wayland but takes more RAM and not good for older systems.
Webpositive works and is fairly stable but slow and sluggish. I think it needs upgrading to WebKit2 to really improve things. This may happen for either R1 or for R2. Just have to wait and see.
Thats actually wrong. You can also help.
Not this year but maybe in 2 to 3 years if Webpositive is still using WebKitLegacy I might actually just push myself to learn C++ better and debugging too and just do it myself. 
Crash issues now resolved using qtwebengine-5.15.2-2.
There hasn’t been an updated _bin package, so as long as that’s not updated in the depot things are still the same I guess. 
EDIT: for the record, did a build and with the updated package it does seem a lot more stable, so far no crashes.
I’m very curious what was the issue triggering the crashes? It seemed to be related to JavaScript garbage collection or something similar
QtWebengine has been rev-bumped to it’s latest changes done by @korli , build against Qt5-5.15.11, so that will be part of the update. Tested so far and no crashes. (progress from previous one)
PS, only for 64bit (but that was already the case)