How to keep the file size of a Logic Pro project within reason?

I am recording cello practicing tutorials for my students, using (for now) just an iPhone XS and recording at 1080p to get started and to avoid melting the device during summer (it's already struggling quite a bit). Upon checking the recordings, I have noticed that, while the cello is clear and prominent, my voice sounds quite muffled and in the background. Some non-comprehensive research taught me that, while the iPhone's mic is omnidirectional, it prioritises closer sources and my voice originates about 30-40cm behind the cello. To work around this, I have used Detach Audio in Final Cut Pro 11 to separate audio from a video. Then, I exported the video as audio only (side question: is there another way to export only the audio from FCP?), resulting in an 85 MB AIFF audio file. After that, I opened the AIFF file in Logic Pro 11 and used the Split Stem feature to separate vocals from instruments, used the Gain Tool to increase the volume of the voice and exported the two tracks separately (about 80-90 MB each, all expected). I did not add any effect, these are videos through which I also plan to learn the craft, so no need to overdo it. The resulting Logic project is 590 MB big! Is this normal? Should I uncheck certain options in the saving process? Is there anything I can do to improve this? Perhaps some mistake in my workflow? Thank you very much!