I know we can create new document profiles with custom size and custom swatches and use the profiles to quickly create new new custom documents with repeating specs.

However either I am doing something wrong or I've missed something, but the guides don't get saved along the artboard size and swatches. Surely keeping the guides should be possible within the same technology? Would love to see this improvement.

I have searched everywhere for a solution to always having to open an illustrator template file as a workaround.

Thanks :)