Figured i'd give the mod author a hand for some frequently asked questions in the workshop comment page. I'll give you the steps to tweak the mod to your preference.

The most straight forward option if you ONLY want to change stack sizes is to use this utility for the storage framework, it will let you modify both the number of stacks per cell and the types of things you can store individually to each of the holds all ingame.
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=3530785055&searchtext=adaptive+storage

If you prefer to keep your modlist lean you can also do this by modifying the mod XML, additionally this will allow you to remove the adjacency limitation to build holds in rows or the substructure limitation for 2x2 and massive holds.

You could even do both things if you so wish, removing construction limitations via xml and managing properties with global settings mod.

Adjusting a file directly may seem daunting but it is a very simple process. You will first need a text editor. For very simple changes like this the default windows notepad will work, personally i like Notepad++ for its depth of features https://notepad-plus-plus.org/

I went for version 8.8.2 that still has manual updates for simplicity.
Steps on either default notepad or notepad++ will be very much the same.

Now the steps.
1- Locate the cargo hold's xml file, you can do this by going to the mods menu inside rimworld, selecting cargo holds, clicking the advanced button on the right and using the "open folder option", once on the general folder, open the "Defs" subfolder, "CargoHold" within that, and you'll have found the file containing the mod parameters called "Buildings_CargoHold.xml".

2- If you like, make a backup if you wish to be safe, although the file can be reset by unsubscribing and resubscribing on the workshop. Right click the file in windows and open it with the text editor of your choosing, regular windows notepad or notepad++.

3- Press the keys CTRL and F to bring up the search bar, this will be our main tool to get changes done. Steps 4 to 6 will cover individual needs.

4- To remove the adjacency limit; use the search bar to look for the parameter "PlaceWorker_NeverAdjacentSameDef". The specific line will be found once for each of the cargo holds located between a "<placeWorkers>" tab above and below it.

You can delete the line "<li>PlaceWorker_NeverAdjacentSameDef</li>" for each hold that you want to build in rows.

5- To remove the substructure requirement for the 2x2 and massive hold; use the search bar to locate the term "PlaceWorker_OnSubstructure". Once again found above and below a "placeworkers" tab.

You can delete the line <li>PlaceWorker_OnSubstructure</li> if you want to build them outside a ship, personally i keep it active as it makes sense to me.

6- To modify stack sizes; use the search bar to locate the parameter "maxItemsInCell", this is multiplied by the physical size of each hold, 1x1, 2x1, 2x2 and 5x5 meaning 1, 2, 4 and 25 times respectively.

Edit the number in <maxItemsInCell>50</maxItemsInCell> for each of the individual holds, for me 10 per cell works fine.

7- After adjusting this via xml you will want to make the descriptions match. This is found by searching the word "stacks" and you will find five entries for the different holds. simply multiply it by each cell on the particular hold so for example with my chosen amounts, 1x1 would be 10 stacks, 2x1 is 20 stacks, 2x2 is 40 stacks, 5x5 is 250 stacks.

Once your chosen adjustments are made, use the option in the text editor to save your changes and boot the game. I would recommend making a copy of this adjusted file just in case to have at hand for future reference as future updates will likely overwrite these manual parameters.

For anyone having issues with the cargo holds showing in the architect menu, the global settings mod could help, and make sure you have storage framework higher in the load order than cargo holds itself, as well as harmony at the very, very top before even the base game and dlcs, just an idea.

Thanks to the mod creator once again, cheers.