When you shoot interlaced (there are many reasons for doing so) you want to edit interlaced.
When you export, if it’s for web or computer screen, you THEN make a progressive version.
If you deinterlace before editing you are losing resolution/quality/information in your footage.
If you’re just converting footage for editing you should stick to the original format as much as possible.
Convert 1080/60i to 1080/60i or 29.97, it’s the same.
Chris