selichos and tachanun

Someone recently got married and the question came up as to whether the presence of the chosson in the minyan removes the chiyuv to say tachanun at the conclusion of selichos, or only tachanun during tefilah.  My son brought a proof from the din on erev Rosh haShana where we don't say tachanun during davening, but we still say tachanun during selichos.  He also suggested that this issue may depend on a  whether saying selichos is a kiyum in tefilah or a kiyum in teshuvah.  If it is a cheilek of tefilah, then the same dinim as apply to tefilah should apply to selichos (Rav Yehudah Deri raises this chakira in his teshuvos.)

Note that the Rambam quotes the minhag of selichos in hil teshuvah 3:4, not in hil tefilah:

ונהגו כולם לקום בלילה בעשרה ימים אלו ולהתפלל בבתי כנסיות בדברי תחנונים ובכיבושין עד שיאור היום

Another potential nafka minah of this chakira is whether women obligated to recite selichos.  If it is a din in tefilah, then likely not, but if it is a din in teshuvah, then the answer should be yes.

I would argue that the Rambam has to distinguish between the two forms of tachanun.  The Rambam (hil tefilah 5:1) writes that there are 8 essential components of tefilah, one of which is bowing.  Later in that perek he explains:

השתחויה כיצד אחר שמגביה ראשו מכריעה חמישית ישב לארץ ונופל על פניו ארצה ומתחנן בכל התחנונים שירצה.

According to Rambam, bowing = saying tachanun.  Tachanun/nefilat apayim is part and parcel of shmoneh esrei (this is one of RYBS proofs to that conclusion).

If this is correct, the tachanun at the conclusion of selichos is a different animal entirely.

All this leads me to wonder whether one has to/should do nefilat apayim when reciting tachanun at the end of selichos.  If the reason for nefilat apayin is to fulfill the bowing component of tefilah, then this has no place after selichos.  I don't know about other sefardim, but I notice in our local Moroccon shul that they in fact do not do nefilat apayim when they say tachanun after selichos.  I believe the usual minhag among Ashkenazim is to do nefilat apayim when saying tachanun.