Uvda d'chol and Borer

I would be interested in your comments before I bother Rav Ostroff with this theory, that any time borer is permitted with a shinui it is because of uvda d'chol and not borer per se:

In truth, all borer for constructive purposes should be prohibited. Because borer is so common and necessary to function and enjoy Shabbat, Chazal made certain allowances. The caveat is that there is a distinction between uvda d’chol borer and Shabbat borer. A shinui on a permitted action too similar to a weekday act is permissible. One could never turn a truly ossur act, either d’oraita or d’rabonon, into a permitted one with merely a shinui.

The Teferet Yisrael in Kalkelet Shabbat identifies three categories of activity prohibited by Chazal because of uvda d’chol:

An activity which resembles one of the 39 forbidden labors on Shabbat

An activity which might lead one to perform one of the 39 forbidden labors on Shabbat.

An activity which entails excessive exertion and ruins the spirit of Shabbat.

Examples:

Filtering slightly turbid water is permitted thru a cloth but not thru a dreg strainer. Slightly turbid water is one min and is not subject to borer; if it were, it would also be prohibited to strain thru a cloth. Proof is that, cloudy water is a taarovis and prohibited to strain thru a cloth. A dreg strainer is the usual weekday tool for straining. Its use for slightly turbid water was too close to a weekday activity so Chazal insisted on a shinui.

One is not allowed to peel the thin skin off peanuts by rubbing them in between two hands or sifting them through two hands, but may separate them by rubbing them with the tips of his fingers (SA 319:6) or sift them through one hand (SA319:9). Peanuts and their skin are two mineem, but one is allowed to separate with his hands before eating or remove the outside cover to access the inner food just before eating. Hands can’t be a kli for separating the definition of a borer kli is facilitating separating which can’t be done with ones hand! Peeling the sifting peanuts with two hands is the normal weekday procedure, one hand is a shinui

Heat can’t be a kli for separating. One can’t hold heat! Nevertheless, one is prohibited from standing “milk in a hot place for it to become cheese” (MB seif katan 63). This is a transgression of mechabeytz מחבץ which is a toldah of borer. Yet what did one do? One is allowed to stand up a bottle of wine and let the dregs settle out, even though the wine in its original state is a taarovis and settling is borer mamish, because, what did one do? Placing milk in a warm location was forbidden by Chazal because it is the uvda d’chol manner of making cheese.