All of the above mentioned techniques have their advantages - one needs to remember sometimes very bad color can create a better black and white image than a well balanced color image too - if the end result is B&W, why care whether the color balance is correct before conversion. Use the Hue and lumnosity of the colors to help create the monochrome tones you want in your final image.
I use the LR profiles sometimes if i am in a hurry, but I have no real love for them. Many seem bland to me, but maybe I just don't play withthem enough to appreciate them.
I do like Silver FX a lot. It is true that if you convert with Silver FX in LR, the changes are baked in - BUT - one can then export both a color version of the image and the B&W version of the image into Photoshop and blend them there in PS, in layers. Or one can export a colored image from LR to PS, and then convert with Silver FX and blend the result in PS, before exporting the final image back to LR. One can create B&W images in Photoshop via Image>Adjustments>Black and White> play with the color sliders
Nothing wrong with shooting RAW and B&W filtered jpgs simultaneously in your camera either ( if your camera body can do that and most better bodies can ) - fast and easy - think red or orange filters for darker skies
There are lots of other programs that can help render monochrome images- Topaz Adjust can certainly do that or one of its fellow apps. Google will find lots of others.
Here is a great grey owl in monochrome from the Raptor Center in Sitka Alaska- probably via SIlver FX - but once I have rendered a B&W I no longer try to recall how I did it. I just wanted the yellow eyes to pop