Q. (Re- question above). My second question is: If that (above question) is OK, could they then accept upon themselves some restrictions. For example, it is popular today for people to do a "media fast" where they don't use their phones or computers. Would undertaking that kind of voluntary abstinence from technology in addition to honoring the Shabbat be OK?
A. On question 1752 regarding a non-Jew that was a very religious dedicated Catholic for many years (actually a priest) and then decided to convert to Judaism. He argues now that finally he saw the real truth. Can he be trusted that he has really abandoned his former strong beliefs, since he may even be deceiving himself, and besides he does not have a chezkas kashrus yet. We wrote: Horav Shlomo Miller’s opinion is that teshuva is open in principle to all, and the truth is to be found in the depths of the hearts of all human beings.
The Rov suggested that in this particular case the gerus candidate should be offered a priori the easier option of becoming a Ger Toshav, or a Noahide who keeps the seven mitzvos. If he is adamant and insists to becoming a full fledged Ger Tzedek, more preparatory time should be requested from the applicant. (some Batei Din as is have a five year waiting period).
The Rov added that a precise and clear expression of denial of his prior beliefs should also be requested by the Beis Din.
Since Noahides are considered 'Chasidei Umos Haolam' or the righteous among the nations, it stands to reason that they should be helped in their endeavour and undertaking. Since it is very difficult to observe any belief or faith based only on negative commandments such as the keeping of the Seven Noahide Mitzvos. It stands to reason that they should be encouraged on this partial resting of Shabbos.
However, they do have the positive mitzva of learning all about their mitzvos and tefilah as part of Emunah.
Horav Shlomo Miller's Shlit'a opinion is that depending on the case, in principle they could be encouraged in their partial enjoying and celebrating of Shabbos.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller and Horav Aharon Miller Shlit’a