Dear Ylatch
It's quite common in some circles by my understanding, but as they say it isnt nessesarally everyones "cup of tea" and I see no shame in the drinking of that cup or not if one chooses.
Within the confines of the group of older kinksters responsible for my initial training there where multiple levels of dominion in existance within the common group dynamic but it wasn't nessesarally sexual in nature or done exactly the way you and others have so far described within the contemporary ideas of a "switch" as an "identity" group where a dom or domme becomes an actual submissive (let alone a collared slave) to another dominant persay.
Though in that group the terminology of "switch" wasn't a titular possibility or nessesity becuase even if one did in fact submit to another in one capacity or another (even sexually), it didn't change their place within the groups pecking order nessesarally if it wasn't a part of the houses affairs or offical hierarchy.
Submissives and slaves in that group had their own internal and fluid hierchial arrangments that the dominants of the house would modify at their whim and the behavior of topping each other (even in a sexual manner) was quite common amongst us.
I did know of one dominant in that group who started off as a submissive first but became a domme later in her life but she was hard as nails and I honestly couldn't see her in a submissive capacity.
Years later I did find two much smaller more casual mor public dungeon type groups, but they didn't take any titular distinctions with any seriousness and often "switched" even with the same partner which I didnt find all that shocking amongst the submissives.
I don't know if it was me or my early training but I was never comfortable with submission of a sexual nature to one who identified as a dominant who I knew was submitting to someone else who may or may not had previously submitted to me etc.
Like if my partner was submitting in front of me in a sexual fashion to another I had just dominated I found it profoundly disturbing. Nor was I able to play along with those who wished to dominante me five days out of the week but have me dominant them for the other two.
It like any aspect of D/s or bdsm may or may not be everyones cup of tea though and as I said before I see no shame in each to their own.
I don't know if this helped any, but I do hope you found my perspective somewhat useful for you. Please feel free to contact me if I can ever be of any further assistance.
I pray that your relationship with your domme be a long and fruitful one all the same.
Respectfully,
denuseri