Editing Large project

This is my workflow for editing large projects.

Source footage: Full HD 1920x1080

1) Only Import the footage which is used in that partiular scene.
2) Convert it to proxy - mjpeg qscale 5
3) Edit the scene and save it and close. (A scene about 5 mins or 3)

4) Create another project for another scene
5) Repeat No.2 & 3 step

6) After all the scenes being perfectly edited create a new project. (Main sequence)
7) Import all the scenes (Importing kdenlive xml as footage)
8) Order and join it together.
9) Render.

The only problem i am facing is importing multiple project file into kdenlive isn't officially supported. Hence all the xml files i import shows as a single footage, which is not good. If i need to do a brush up of that particular scene i have to open the project again, and it gets updated in the main sequence.

I want to know how you guys edit larger projects. Because editing more than 20 mins of projects with large number of files, kdenlive is unstable and crashes. So I opted for this workflow.

What's the workflow of you guys.

Feature request:
1) While importing XML project into kdenlive try to import the whole project and not like a footage.