I've heard that shvus dshvus dshvus (like asking a non-Jew to do a melacha drabbanun with a shinui is permissible. Is that only bidieved or lichatchilah as well? Also is it a machlokes? Please bring sources.
R Daniel Braude (Learn Shabbos, p.p. 534-35) explains this is indeed possible but the details are a machloket. He permits telling a non-Jew to do a melachah with a shinui in cases where the result will be inferior. Specifically
When a Torah melachah is performed with a shinui it is no longer classified as a Torah prohibition, as it has changed from the typical melachah itself. However it is still Rabinically prohibited. Is the halacha in a case of a melachah done with a shinui more stringent than the Rabbinic prohibitions mentioned above, because the melachah itself is still occurring?
There is much debate about this. Although the Mishnah Berurah is lenient in certain cases, one must consult a Rav before applying this leniency to a melachah that is done with a shinui.
As a guideline, the following thought process is considered credible, and may be applied: R Yosef Shalom Elyashiv and R Shlomo Zalman Auerbach distinguished between a shinui that produces an inferior result to what would result with a normal melachah, and a shinui that ultimately causes the same result. In both cases it is a Rabbinic prohibition, but where the result is inferior, it is less of a melachah, and using this leniency is permitted. However, where the result is identical, this leniency may not be used.
As an example
- if one taps a light switch with his elbow, it is abnormal, and qualifies as a shinui. However, the light would not have been different if one had switched it on normally. The quality of the act is the same, and so, one may not ask a non-Jew to switch a light abnormally for a great personal need
- on the other, if one writes with his weaker hand, the quality of the writing will certainly be inferior to that of his natural handwriting. Therefore, one may ask a non-Jew to write with his left hand in a case of great need
Note that in cases in which the non-Jew was told to do the act with a shinui and he decided to do it normally, one may still benefit from that melachah, unless the expectation of the non-Jew doing it in such an unusual way was unreasonable. In other words, this leniency (telling a non-Jew to do a melachah with a shinui in cases where the result will be inferior) does not apply if the non-Jew will almost certainly stil do it in the normal way.