The truly difficult part comes now: how to encode the remaining 16 suit combinations? I’m going to propose a standard solution, but I’m going to propose alternative strategies as well. You may pick the one that you prefer.
First, let’s name the strategies:
Sublocus Strategy: this strategy consists of dividing every locus of the memory palace into 2 (2-sublocus strategy) or 4 subloci (4-sublocus strategy). For instance, you may divide each locus into wall and floor, into right and left sides, or left side of the wall, right side of the wall, left side of the floor, and right side of the floor. This requires prior planning of the memory palace, especially if you want to divide it into 4 parts. In the 2-sublocus strategy, put the image inside the first sublocus if the second suit is 
or 
; put the image inside the second sublocus if the second suit is 
or 
. In 4-sublocus strategy, put the image inside the first sublocus if the second suit is , inside the second sublocus if it’s , inside the third sublocus if it’s , and inside the fourth sublocus if it’s .
Agent-Observer Strategy: we mostly imagine ourselves as observers instead of agents when memorizing. However, we can also imagine ourselves interacting with the images inside the locus. This strategy can be applied in two ways: Current-Agent-Observer or Next-Agent-Observer. In the former, we do the following: if the second suit is red, then I’m an agent interacting with the current image; if the second suit is black, then I’m an observer (I don’t interact with the current image). In the latter, we do differently: if the third suit is red, then I’m going to be an agent, interacting with the next image; if the third suit is black, then I’m going to be an observer, not interacting with the next image.
Variable Image Stacking: this is the only strategy not invented by me. It was invented by Johannes Mallow. In our context, It consists of putting the image in the current locus and going to the next one if the third suit is red; otherwise, keep putting images in the same locus;
Variable Story Stacking: most of us memorize by creating stories with our images in the memory palace. Some people create continuous stories (like legendary Ben Pridmore/ @Zoomy, who has commented on this forum that the loci work just as backgrounds for him). Others may cut the story at the end of locus. Some may even cut the story at the middle of the locus. Since the end of the story is independent of the end of the locus, we can use it to encode information: if the third suit is or , then stop the story; if the third suit is or , then keep the story going.
Now that you understand each strategy, you can choose them according to your preferences to encode the remaining 16 suit combinations. I would recommend three possible combinations. The orders were chosen to make visualization as fast as possible.
16 SUIT BLOCKS
In my opinion, the second option is the best one because it isn’t too rigid and wouldn’t require me to divide my loci into too small spaces, but other people may disagree.
ENCODING
For any of the options, you should start by spotting the first suit. It will determine the list of formation codes to use. After that, read the ranks of the cards and convert them into a 4-digit number/image. Afterward, you need to apply the chosen strategy(ies) to encode the second suit. Finally, the strategies for the third suit tell you how to behave in the next locus, like “stay in the same locus” or “keep the story going.”