A repeating complaint I run into with the more impressionistic reconstructions found in the UEW is the frequent use of *ŋ as a kind of a deus ex machina phoneme, reconstructed for all sorts of confusing correspondences of nasal consonants. One offender is the word for ‘raspberry’, given as *äŋɜ-ćɜ. No reflexes are known from Samic, Finnic or Samoyedic, which often spells trouble for working out the overall root shape; and a lack of reflexes in Finnic or Hungarian in turn spells trouble for coverage in the etymological literature. All the remaining Uralic branches still have reflexes though, ranging from Moksha to Southern Khanty, so there is probably still something native Uralic in here, not just late areal loanwords (in Mansi this is regardless a clear Komi loanword).
A casual look over the reflexes indeed reveals a clear /ŋ/ in Mari (Meadow /eŋəž/, Hill /əŋgəž/); and the Khanty reflex *-ääńć only appears as a latter member in compounds, and hence could be expected to have gone thru a bit more reduction than usual anyway. But this is about as far as we get before things stop working.
In Permic we find /m/: Udmurt /emedź/ ~ /emeź/, Komi /ɤmɨdź/ ~ /ɤmidź/ ~ /ɤmedź/ (probably < PP *ɛmedź). This is not an entirely unprecedented reflex of *ŋ, but usually development to *m only takes place adjacent to labial vowels, and even then should be usually retained in various Udmurt dialects. Compare e.g. PP *pɔŋ ‘head’, whence northern and central Udmurt /pum/, southern Ud. /puŋ/, most Komi /pon/, northernmost Komi /pom/.
Within Mordvinic, Erzya /ińźej/ ~ /ińźeŋ/ (also /ińdźej/ in Paasonen’s dialect data) could seem to suggest syllable contraction and POA assimilation similar to the implicit Khanty development: *-ŋVć- > *-ŋVź- > *-ŋź- > /-ńź-/? However, this fails in light of Moksha /ińəźi/, /ińiźi/, which has evidently escaped syncope, showing that the word was still trisyllabic *iNəźəŋ in Proto-Mordvinic. But medial *-ŋ- should then have definitely yilded **-j-! A development *-ŋ- > *-ń- that is probably being supposed here is otherwise entirely unknown in Mordvinic. Same would go for any kind of a suggestion of secondary epenthesis *-ńź- > /-ńiź-/.
Even in Mari there is the further problem that Hill Mari /ə/ does not regularly reflect PU *ä. This, however, could prove to be the key to the problem. We do find at least one other parallel for the correspondence MMa /e/ ~ HMa /ə/ word-initially, which I think is not accidental: the verb /eŋa-/ ~ /əŋgä-/ ‘to burn’ (from PU *äŋə-, demonstrating also that in Komi the expected reflex of *ŋ in a front-vocalic environment is /ń/). Raspberries happen to have a natural connection to fire: in the taiga zone, they are a typical pioneer species thriving in forest areas cleared by wildfire, sometimes in quite good abundance until crowded out by a shading tree cover. So I will suggest that the Mari name of the raspberry is in fact directly based on the verb stem ‘to burn’, and the “suffix” /-əž/ is what actually brings in the meaning ‘berry’. In light of Khanty, I will further suggest this is indeed an old compound, with the second member continuing a simpler root *äńćä ‘(rasp)berry’.
The other reflexes can be probably treated as compounds as well. In Mordvinic the first member could be perhaps identified with the first syllable of *ińďəŕ ~ *ińďəŋ ‘honeysuckle’ (which grows red compound berries similar to the raspberry) or *ińə ‘big’ (the raspberry grows fairly large berries even in the wild, unlike other culinarily important species such as the strawberry or blueberry). For Permic *ɛm- I do not have any etymology; however, a compound analysis seems to gain some other support from the fact that there is no real evidence for a “suffix” *-edź in Proto-Permic. And then among the very few words showing this ending, another berry can be found too: *pɛledź ‘rowanberry’. Usually this has been taken as a somehow heavily divergent reflex of PU *pićla ~ *pićrä ‘rowan’, and there could be some of this source still involved after all. But PP *pɛledź would also come quite close to a compound of *pȯl ‘time, instance’ + my already hypothesized *-edź ‘berry’. Hence: ‘many instances of berry = clustered berry’, as at least a folk-etymology? *ɛ ~ *ȯ are not quite identical, definitely not if read as IPA [ɛ] and [ɵ]; etymologically they are however both primarily reflexes of PU *ä, coincide in having /ɤ/ as their main reflex in Komi, and Zhivlov (2010) has even already shown that the two are in a complementary distribution in a fairly large number of environments; though the topic will probably still need some work.
A few other berry words have been reconstructed for PU as well, the clearest is *mura ‘cloudberry’, and also *pola or *pala ‘? lingonberry’ is quite probable. Finding any really new etymologies in this semantic area would likely however require first looking at each language group’s berry terminology as a whole… One precedent for this exists, a case study of Finnic berry names by Eino Koponen: “Itämerensuomalaisen marjannimistön kehityksen päälinjoja ja kantasuomen historiallista dialektologiaa”, 1991 (SUSA 83: 123–161); and what this reveals is absolutely rampant analogy, e.g. that Finnish puolukka ‘lingonberry’ has likely been rebuilt almost entirely after/in tandem with juolukka ‘bog bilberry, Vaccinium uliginosum‘, or Fi. vadelma ‘raspberry’ evolving in some dialects, after some other steps, into vaarain under the influence of muurain ‘cloudberry’. This possibility will probably need to be taken into account elsewhere too.