Eikev: Developing Our Own Liturgical Practices

The commentary in the present-day Reconstructionist Kol Han'shamah aptly describes the problem in this paragraph: Its detailed description of the "bountiful or devastating consequences of Israel's collective relationship to the mitzvot...offers a supernatural theology that many contemporary Jews find difficult." Simply put, it presents a doctrine of reward and punishment that most liberal Jews have found problematic, if not offensive. It has therefore been removed from most liberal prayer books in the modern era.

Usually, no alternative is provided, but the Reconstructionist liturgy of 1945 substitutes Deuteronomy 28:1-6...The Israeli Ha'avodah Shbalev provides a similar option: Deuteronomy 30:15-20...Like Kol Han'shamah, however, Ha'avodah Shbalevoffers it only as an alternative, not a substitute.
David Ellenson, My People's Prayer Book, Vol. 1

"...In the first trial-draft of Mishkan T'filah (2002), which included the second paragraph as an option, noting that 'traditional Reform thinking challenges Deuteronomic theology, that bad events which occur are a result of communal sinful behavior. We do accept responsibility for social and natural ecology: how we treat one another and our environment has a powerful, direct impact on society and the planet.'
Nonetheless, the verses describing an angry God 'sealing up the heavens' were printed in smaller type, acknowledging the theological difficulties with this image. The paragraph ultimately remained sufficiently problematic to require both a recommendation from the Siddur Editorial Committee and a vote by the CCAR Executive Committee. Both decided to uphold the earlier Reform deletion of the paragraph in its entirety: even though subject to mitigating non-literalist interpretations, the text itself remains difficult for a modern Jew to recite in the liturgy --although the second reading on page 235 (117 Shabbat edition), 'If we can hear the words from Sinai,' by Rabbi Richard Levy, is in fact a contemporary interpretation of the second paragraph of the Sh'ma.
The third paragraph of the Sh'ma is variously referred to by the Rabbis as parashat tzitzit, since it deals with the obligation to wear fringes on the four corners of one's garment that are to serve as reminders of God's commandments, and as Y'tziat Mitzrayim, 'the Exodus from Egypt,' since at the end it refers to God as the One who redeemed the Israelites from Egypt.... When the custom of wearing a tallit during morning prayers became less frequent among Reform Jews, this paragraph came to be dropped from the liturgy (...the Berlin Reformers, Einhorn, and the Union Prayer Book were typical of this trend; the 1918 revision of the UPB reinstated a portion of the final part of the paragraph, beginning L'maan tizk'ru the full conclusion was reinstated in Gates of Prayer, 1975). Now that many Reform Jews wear tallitot at morning prayers, Mishkan T'filah has restored the entire third paragraph as an option for those who wish to recite it--but only in the morning, since the tallit is not worn at night." -- Sarason, Rabbi Richard S. Divrei Mishkan T'filah: Delving into the Siddur. CCAR Press, 2017. p 42-43.