In a practical sense, logging of sim time should be restricted to the sim column in your logbook, only. Don't include it in total times, or any other category. Don't add it to PIC time, SIC time, or try to define it by category or class.
If sim time is added to totals, it can cause real headaches when attempting to define time categories for insurance, employment, carding, etc. Generally speaking, single time, when added to multi time, should equal total time. PIC, when added to SIC, and instruction received which isn't either is accounted for, should add to total time. Having a total which doesn't match other categories when added or subtracted can only cause problems.
Of course, the only time required to be logged is that used to meet the recency of expeience requirements, or the experience requirements for any certificate, rating, or operating privilege. Outside of that, you can do what you will. However, adding sim time to total times, and especially to category and class, can wreak havoc in the interview, and may certainly give the appearance of padding one's logbook.
I did the same thing years ago; I had gobs of sim time listed in my log, and it was classified in total time, and category and class. However, I finally realized how it looked, and adjusted my times by removing all simulator and flight engineer time from any other total, except the respective sim and FE columns. It's a good idea; it makes your log much cleaner, and removes any sense of impropriety.