I played F.T. for a couple of months (or, at the very least a few days away from two months). I feel as if, while I think without a doubt thing F.T. should become more complicated, this is kinda going about it in the wrong way. That said, due to my experience a lot of this is going to be anecdotal.
First off, let's start with the biggest problem I have with it personally. It makes the F.T. even more of a pure supporting role to the Detective. As it stands now, the F.T. is designed to be a support role and help figure out cases without getting (personally) involved by chasing down criminals and so forth. Along with that, many officers seem to disregard evidence from the F.T., but will listen if it comes from the Detective. Not to mention that more often than note, Detectives won't really share information they get with the F.T. but except information from the F.T. themselves. Now, in my experience there ARE exceptions to this rule, and there are some really good Detectives who will do all in their power to keep the F.T. in the loop, but I found that in maybe one Detective regular. By doing this, you're simply giving the Detective even less reason to keep the F.T. in the loop, because the Detective is going to know what they saw and interviewed and so forth. To phrase it better, the F.T. will just be handing off really simple information that they personally can't link to anything, and giving it to someone who can link it to something. While that may sound like a good dynamic on paper, this dynamic already exists at our current level but ensures the F.T. can actually contribute more to the case.
Being a glorified assistant to the Detective has always been all fine and good though, because as it is now, the F.T. can solve a case on their own, and that's part of what made F.T. really enjoyable. Being privy to information nobody else has, and being able to link blood samples with fibers and so forth to be able to solve a case was incredibly rewarding. By removing their ability to distinguish the specific articles of clothing, you lose out on that ability. Now, the F.T. is incredibly reliant on a Detective being present and willing to work with their results (which could be a mixed bag). Sure, the F.T. could go around questioning people themselves, but at the same time if that was the case what's the point of having the two be separate jobs. Not to mention the fact that I could already see this being a headache to try and figure out for a F.T. since you already have issues with things at the scene being contaminated. The issue of contamination has been a discussion a few times in the past, and is relevant here again. For example, let's say there was a break-in on the bridge. You have fibers from the Chaplain's jumpsuit, an Engineer's jumpsuit, the Captain's jumpsuit, black gloves, a labcoat, and a tophat. This gives the Detective and F.T. a starting point to go off of. It allows them to know who to question, and try to help deduce the likelihood of possible suspects. Maybe these people just bumped into the door, maybe they broke in. You don't know until you question them, but at least you have a starting point. With just giving colored fibers, there's basically no starting point for the Detective or F.T. to go off of. Blue fibers could be a random blue jumpsuit from the locker, or it could be the Captain's. Or maybe it's a blazer, or maybe it's a suit. Now all of a sudden your suspect pool is still the entire station with something blue because you can't narrow it down. The F.T. should have specific readouts, because it ensures that there's a benefit of actually having them on the shift, and gives both the investigative members someone to talk to which in turn ensures the Detective has something to do, and the person they're questioning is being given roleplay. With fibers, the Detective may just decide it's too much work and forget about it OR the last issue could crop up and nullify the results.
Time. Time goes by really fast compared to real life on SS13. A medical procedure that would normally be rather relaxed is now suddenly hectic because you're having all these patients coming in and you're having to triage every single one of them at a fraction of the time you would have in real life. In the case of security, once a situation occurs where the F.T. is needed, the situation is going to expand rapidly. As a F.T., you're having to try and piece together information from blood samples, fibers, and fingerprints by going through the records to try and find a connection to a crime and a suspect. For example, when I played F.T. I would leaves notes for the Detective/HoS regarding how each piece of evidence connected to each other, and would put them in a stack before handing it off to the Detective. That sounds like it'd be short, but it take up a considerable amount of time (especially when you're factoring in the F.T. having to handle autopsies on top of all that), since you're having to cross-apply all the evidence you're getting and present credible linkage. By the time you do it in the normal style, while you can usually get this done with enough time to help aid the case, you still might find out that the case has ended, or that the Detective has caught their suspect (even though the case started not even five minutes ago), or simply that more important matters have come up. By giving the F.T. generic fibers instead of specific ones, you exacerbate the issue here. Suddenly, the Detective and F.T. both have less time to work with and are much more rushed to get things done which can lead to the evidence being dismissed or just outright ignored because of the lack of time. In a real life setting, this may work but with most single cases taking up (usually) less than an hour, it's simply not feasible for the F.T. or Detective to run around trying to interview every single person with a set of fibers while at the same time trying to link other pieces of evidence and interview statements.
In the end, no. The F.T.'s results aren't "utterly broken" because without them being as specific as they are, it takes away from the role which in turn makes the role even more boring which then causes less people to want to play.