This campaign has quite a few expectations which you should share with your players, which this page will go through:
This campaign, and I mean, MOST of this campaign is about shopping for items. When you first start the campaign, your players will get a certain amount of gold to decide what items they need. They'll consider what they need to bring with them while DELVEing, heavily consider what they will need when they have to turn back, and then spend even more time shopping and learning about newfound items.
This campaign is designed so that either you are playing-by-post or partially online. If you have only a few hours for a session, you will most likely have to dedicate it entirely to shopping. The items in this campaign are designed to facilitate more than just a gameplay discussion, which is mostly for YOUR benefit. As a CM (Cave Master), you should be as hands off as possible in determining exactly how the players prepare for the DELVE, which means you will have to spend some time sitting there while your players fret over every single item they bring along. To optimally play time limited sessions, the players will prepare a list of everything they want before they arrive at the table and make only minor alterations beforehand. You can push this as an oppurtunity for players to connect outside of the session if they feel comfortable.
Otherwise, embrace fully the experience of being outside of the cave. This may be one of the few oppurtunties for characters to roleplay safely- and potentially the only oppurtunity if a character should perish within the cave. It is important for the characters to form bonds so that dramatic moments can really be felt. Also, death need not be the end- if the players feel lukewarm about a character, they'll be indifferent to going a dangerous rescue mission!
As a CM, most of your job requires knowing what is ahead of the players and knowing what is behind, and all of the pages provided for you will provide all the information you need to do that. One of the most important distinction is letting everything the players use leave some remenant on the cave. Many typical RPG sessions quickly move through content and don't connect events together for the sake of efficiency, usually under the assumption that it is impossible to predict exactly what the players will do, but the cave is built around almost contantly moving back and forth through it.
The best thing at your disposal is the "Perfectly Organized Cave Guide" [WIP]. Serving as a massive organized noteboard for all your needs. Generally is segmented by each delve level and every single location within that delve level. It lists items, encounters, creatures, and characters waiting for the players when they arrive and leaves with links and references to all the information about them. It also has a ton of space to (hopefully) list any items the players leave behind, with specific sections for some of the most important objects- like ropes going up walls and fixed pitons.
The CM guide is designed to be read both forward and backward- completely new descriptions are given based on if the players are leaving the cave. Sometimes it simply alters the perspective, changing up to down, but sometimes entirely new details are revealed. It also offers new and thrilling hazards to keep players on their toes even when navigating locations they've been before.
From a resource perspective, The DELVE is supposed to drain the resources, and the ESCAPE pushes the players to their limits. The ESCAPE will get longer and longer as each delve goes deeper and deeper. As such, the ESCAPE is designed to threaten less resources and be much more directly threatening. You can always shake things up for dramatic effec, but consider simply letting things take their natural course- especially to reward players who plan exceptionally well.
A truly risky trial, if the players feel that they have plundered all their is to offer, than they (for cost) and attempt the MASTERY RUN. This, as expected, requires one character to go as quickly as possible through the cave depth. This will open up a teleportation gateway which will allow them to skip a portion of the DELVE. This is only HALF MASTERY. For an even harder challenge, they'll need to run all the way to the bottom and all the way back in one run. Allowing them to skip the DELVE and the ESCAPE.
Teleporting to and from base camp down to an existing depth can be done for completely free, but teleporting within the caves requires limited resources. By spending flares, which provide light down in the caves, items can be sent, and for lots of flares, living creatures can be sent too. Certain layers might want to be skipped to avoid specific hazards so that packing can be changed as needed.
This might be somewhat complicated, as HALF MASTERY is possible before FULL MASTERY. IF you think of every depth like a race course, then you can race it both up and down for two half masteries to create one way links. However, FULL MASTERY is only possible by creating a two way link which dramatically reduces resource use for teleporting. Longer loops are always better! Generally, creating a two way loop over a single depth will be the most consistent strategy, but a surface loop is the most beneficial and the most difficult.
Could a mythical full loop be possible? Well, at that point, the campaign is probably already over, but I would suggest that being a final sendoff for any campaign.