This is a “is this normal” question.
I am using VSCode and .rbxlx files to use rojo and it takes a significant amount of time to save the file, in contrast when I save the same file as .rbxl it saves instantly. Is this normal?
Do I have to use .rbxlx files and go through the enormous save times to use rojo?
You can just edit a game in the cloud and sync it with Rojo. This way, you do not have to save it locally.
I want to save it locally.
Yes, this is normal as .rbxlx saves places in XML File format, while .rbxl saves the place in binary which in contrast has ~1000% smaller storage footprint and ~750% faster load/save time.
For more information, you can read this blog article about it made back in 2013:
https://blog.roblox.com/2013/05/condense-and-compress-our-custom-binary-file-format/
Note: This number may be have changed since then but the point still stands even now.
Another note is that I might have calculated percentages wrong because of my lack of understand conversions between percentages and multiples.
Is it possible to use rojo with .rbxl or no?
Rojo can work with .rbxl as far as I know. Thought you should test it out first to be sure.