Q. Is there a point on just having kavanah at the end of the brachah, if you can’t do it complete?

A. Mishna Berura (101: 1) quotes the Tur (ibid.) who maintains that one should have kavanah at least on the end of every brocho of the amida. The Tur mentions as a reason the fact that the sum of the words in all the end brochos of the amida is 113. This is the same number of the words in Chana’s Tefila (a source for many of the halachos of tefilah) and the same amount of the times that the word “lev” or heart in its different forms is mentioned in the Torah. (See also Baal Haturim at the end of Pashas Pekudey)

Horav Shlomo Miller Shlit”a further explained that the most important and relevant part of the brocho is the ending, as it contains the name of Hashem and the brocho formula.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a