I thought about doing that but that space is really tight and changing filters would suck. I'm thinking about doing a writeup on an install of a prefilter below the stock filter that can be accessible from below during an oil change and using this as your secondary/high efficiency filter ( which should be changed more often anyway. And fabbing up an air remover like a BullyDog system.
Now if I can just talk mother nature to STOP WINTER!

There are very good reasons why large machines have 2 filters. Tractors & earth moving equipment for example. You are more likely to have an issue with a filter passing unfiltered fuel than many realize. Having 2 filters in series protects against this. Many people change the primary more often than the fine secondary. its best if you have a bowl on both filters to allow checking of what the filter had removed. I have a primary filter on my bulk tank at home. It shows that there is plenty of contaminants in fuel from the supplier.

Fuel Filter Importance in a Modern Diesel Engine
Yes, the stock filter can supply the fuel, but what the stock filter cannot do is filter it down to 2 microns or less to help protect the CP3 and most importantly the very expensive fuel injectors. Fuel filters are very cheap insurance indeed.
Today’s diesel engine manufacturers have increased their fuel system injection rail pressures upwards of 30,000 PSI. The higher injection pressures result in better atomization of the fuel which effectively reduces emissions. Conversely, these higher rail pressures can increase abrasive wear of the injectors and the injection pump internal parts which are cooled by the fuel thus making it more important than ever before to select proper filtration equipment that is appropriate for today's requirements. Proper filtration must adequately remove the two worst enemies of diesel engines: water and particulate contaminants.
Microscopic particles (>2 microns) that can make it through inadequate fuel filter systems are very abrasive at the extremely high injection operating pressures of the diesel engine fuel injection system. Much emphasis should be placed on selecting high quality filters that can efficiently remove microscopic particle sizes down to <2 microns to help protect against long term engine injection system wear, damage, and / or possible failures.
It is not the CP3 that is of most concern, although it certainly should be considered, but the four very expensive fuel injectors. One set of failed fuel injectors due to contaminated fuel can cost a small fortune to replace or even to have rebuilt by a certified Bosch rebuilder.

The cost of ONE fuel injector will buy an awful lot of high-quality 2 micron fuel filters.

For any diesel engine to function properly for a long period of time, it needs to be well maintained and it must be supplied with clean, high-quality fuel. Cleanliness has always been an important part in maintaining the performance, reliability, and usable life of a diesel engine. But in today’s high pressure common rail fuel systems, the extreme close tolerance components require a much higher level of fuel cleanliness to prevent long term damage or wear.
Over time, Microscopic particles smaller than 10 microns that are not captured by a primary filter/water separator can cause damage & wear to the injection pump internal parts and / or fuel injector's very close tolerance internal parts.

With the exception of personal driving behaviors, ^*+the efficiency and tightness of fuel injectors is the single most important factor that can affect fuel economy and performance in a modern diesel engine.

But as always to each his own, it is your vehicle and you are your own warranty provider. As for me, I like providing as much additional protection where possible, especially when it is as cheap as adding an extra fuel filter or two...

^DIESEL FUEL INJECTOR ISSUES
*Clean Injectors Fuel Maximum Performance and Productivity
+Effect of injector nozzle parameters on fuel consumption and soot emission of two-cylinder diesel engine for vehicle

Like this?

Looking at your sign. What is a Kap 193 thermostat?

I remember that thread from years ago. I think I still have a housing around here somewhere I was going to fab up. Was there ever a final parts list?

Whatever makes you happy. I've never had 2 filters (or even one with a water separator on either of my Dodge diesels. It's important to know where you get your fuel. If you get it from questionable locations then by all means. Also make darn sure if you are using an alternative filter that it is for fuel and not oil or hydraulic fluid as those have a bypass if they get clogged.

The stock fuel filter on your Dodge diesels were more likely than not also water separators (probably Mopar 68084905AE which Mopar calls a Fuel/Water Separator). The stock fuel filter on the Jeep Liberty CRD also acts as a water separator (i.e., Mopar 52129238AA which has "water eliminator" printed on the filter itself). Both of these fuel filter systems include a drain valve to allow you to periodically purge any water that the filter/water separator rejects. The Dodge has the drain on the filter housing, the Jeep uses the WIF sensor as the drain plug on the cartridge itself.

Unfortunately knowing where you get your fuel will not always prevent you from getting any water. That's why it's even more important to have good filtration.

BTW, the Dodge diesel OEM filtration allegedly didn't even meet Bosch's minimum requirements for the OEM injectors. You gotta wonder if the same is true for the Jeep OEM filtration.