Over to Borg-land for Castaway and Stranded. As I've said before, I've never read or played Mork Borg. I know it's rules-light and art-heavy. I got Pirate Borg because Pirates! Then I backed Castaway because it seemed perfect for when your pirates end up without a ship. The book is art heavy, but the colour-scheme is sepia, dark-red-ish brown or light green. Text is always contrasting and well spaced, so it's much easier to read than Pirate Borg, although 4 pages for the D10 weapons table is excessive. Other than the the d# dice in the text, all numbers outside of the index and end end-paper are roman numerals. At first, I thought "on page XC" was a typo or leftover placeholder.
Castaway is a lighter game than PB - I suspect much closer to MB. I scanned the PDF a couple of months ago, and was disappointed, but am much more bullish on an actual read. This is a case of rule-light means "the GM needs to fill in the blanks" but most of what you need is there, so you're interpolating, not making things up from whole cloth. Premise is you wash up on an island. You're got nothing but what you find on the beach. And you need to escape or be rescued before you die of old age. Or just die. Good rules for camping, foraging, fatigue and resting. Harsh rules for jungle exploration. A small, but thematic bestiary. Eight adventures you can drop on your island that seem totally random, until you realize they're all fetch-quests to get the things you need for the 8th. That one has good, but not explicit, hooks to tie the previous seven adventures in. I think they're pretty obvious when you're reading it, but when I run this, I'll be putting a lot of planning on how to seed it all. Otherwise you get an completely OOG go-find-that-and-come-back. The adventures all have different amounts of required prep. The first three could be dropped out of the book. You'd need to be much better at improv than me for the remainder.
Stranded is the solo/gm-less supplement but almost all of it is good for GM prep. d3 loadout/history. d6 what happens after you escape (6 is a sneaky tie-in to PB). d6 + d24 island type/feature generator. The usual solo exploration generator. The decision oracle encourages you to have an obstacle, benefilt, drawback, consequence and reward for every "path" you're considering - good advice for a GM, too. The Failure spark table is really well done with lots of difficulty-dependent ideas. Rules for yielding, extra reactions, rules for companions and self-improvement (mostly through failure).
The best part is the Nemesis rules. In the Castaway bestiary, there are 2 or 3 creatures that will go lick their wounds if you break their morale, then come back, better prepared, later. Stranded extends this to any fight - if something flees, roll to see if they become a nemesis.