Is :mt: cluster legal?

Lálan! Mára. I linde *ísima minya téma attanen. Kantar i linde yo kamtalelyo [adaptation] ankorne [symmetric]. Ea apaite ar merya enkarda nolmenyan:
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+Ицхак Пензев I searched this myself; Eldamo lists it in precisely one Q word that I actually ended up using in my Q reply. However, :nt: is vastly more common. Ambatira (cf. undulav-) seems like an alternate possibility.
eldamo.org - Eldamo : Quenya : camta-

The reflexive pronoun inte also has a variant imte.

+Robert Reynolds indeed amba- may be better but it looked too long for me - not that it really mattered in this case:)

+Robert Reynolds ísima? apaite? ma tanante?

+Tamas Ferencz *ísima "ascertainable" < ista​-​ + ​-​ima with strengthened stem per distinction described in PE22:111,156. There is attested istalima from PE22:111; this is my attempt at an alternative possibility since it's unclear to me whether ​-​lima for weak verbs survived later (I can't find it outside of that section) and ista-​ is so delightfully irregular.

apaite "touching, *impressive" < ap​-​ + ​-​ite

+Robert Reynolds thanks. I like the -lima ending and tend to use it wherever possible.

+Robert Reynolds wouldn't that be *appaite?

+Tamas Ferencz From VT44:26 (I can read it directly now!), "Also the verb ape is used fig. as to touch one, concern, affect. In literal sense the strengthened weak verb appa is mostly used." So, since the touching/impressiveness is figurative here, ap- seemed fitting.

+Robert Reynolds good point. Mea culpa