JoeBob. It does have to crop your footage but version 4 crops very little for what it is able to do. I was surprised when I tried the initial release. I did a tutorial for Mercalli that is on the product page at prodrenalin.com (
https://www.prodrenalin.com/mercalli-v4-sal-plus/). In the tutorial you can see as I am processing clips just how little is being cropped compared to how much correction is being made. It is pretty impressive just how little does get cropped.
It does export a 1080p file. Granted the footage is really a little lower rez but the file is a 1080 file. The amount of cropping is all based on how bad the original footage really is. If it's just a little shake from wind pushing your copter around even with the gimbal it's going to do amazing with very little crop. You see in the clip above what it can do with bad footage. Will the final clip be a full 1080....no it can't if you fed it a 1080 cause it does have to crop. Now if you feed it a 2.7K or a 4K file you are going to have lots of resolution to play with before going below 1080.
You can download a free trial version on the site as well. It's fully functional but will watermark your footage on export. You can get an idea though. If you decide to purchase a copy let me know and I can get you a coupon code for 20% off. Check the product page and watch some of the tutorial. Mercalli is going to be great for gimbal footage that just needs that little bit of extra clean up.