Also, remember that the ppm reading from and TDS pen is a conversion. There are several different conversion factors in use depending on the brand of equipment you buy (somehwat regional but no gaurantee of uniformity, either). This means it's a trash number that doesn't mean much. Relative to your one garden it is fine but it won't always translate to others in a meaningful way (i.e. not an apples to apples comparison). The EC is helpful, but it is a correlation to actual PPM. it can be inaccurate, obviously by the several conversion factors in use... whehter you buy a "Hanna" product (500-scale) or whatever you have (700 scale i assume), you get different PPM readings for the exact same solution and they are drastically different numbers, lol. Useless to others. You can build familiarity locally, but those numbers may mean different things in different contexts despite same reading.
So, these readings need to be put into perspective. 3.2EC might be okay. If the plant is healthy long-term (not just 'this week' or some short frame of time), then it's fine.
FFOF is a hot soil. Adding coco (comes devoid of nutes) will reduce that a bit. FFOF alone might feed your plants for 8 weeks and does not require much in the way of fertilizer during that period of time. So, consider how much coco you have, reduce that 8 week estimate proportionally, and compare to when you actually added fertilizer and if it was too soon, you probably have a buildup. If you were adding fertilizer too early, it could be a build up you want to dilute going forward. If you used the plant's growth and progression to determine when to start supplementing fertilizer, you are probably fine, but still may need to adjust based on how the plant grows going forward.
The plant tells you everything. The measurements can help, but you need to learn what the 'good' values are before you assume what range of values are proper. The type of fertilizer products you use may impact what 'good numbers' you see. The concentration you need will depends on numerous factors too... it's trial and error process. With soil if you buy the same prodcuts you can gain familiarity. if you go soilless it's more apples to apples and you can receive more specific instructions down to ppm of each nutrient element, but that is not the case with soil.
Soil fertilizers often can have a very high EC but not be toxic to the plant. The greater portion of ingredients that rely on microbes to break it down into plant-useble molecules that can enter through the roots means the EC will be higher. you have the electrical conductivity (EC) added from what the microbes break down AND the products of those interactions that are plant-available. This does not mean double, but it could.. depends on the rate of input-to-output for any one molecules being chelated or fixed etc. Not something to assume, but it definitely is happening with some 'soil' fertilizer ingredients.
So, keep an eye on the plants. What "should be" is fine to start, but you need to adjust based on the reality of the plants growth. Symptoms require an adjustment to the formula and you can avoid those symptoms next cycle etc...
If you want a more accurate understanding of the PPM of your fertilizer and have gauranteed analysis labels, there are free apps that will calculate this stuff for you. This will be an accurate PPM value vs the TDS conversion trash readings. Also, it'll be an apples-to-apples value comparable to other gardens unlike the EC-calculated ppm value.
Also, add perlite or similar to FFOF if you keep using it. Coco won't even out the gas:water mixture in the volume of substrate. FFOF comes with ~20-25% perlite? bring that proportion up to 50% - doesn't have to be perlite. Vermiculite is actually a better option as it adds some silica and can retain nutrients unlike perlite while still giving proper gas mixture for healthiest roots possible.
or, go 100% soilless and buy a set of soilless nutrients. Basically, shit or get off the pot. Lean into soil or go soilless. the hybrid stuff is akin to masturbation and has no real benefit. If coco isn't processed properly by manufacturer it can also make plants sick and even kill them at times. It's a hippie product that got popular but realyl doesn't deserve the hype around it. It's just something that absorbs water and that can be done more easily and with less risk using other products.