There is no way to mark such information on the person records. However, the 110 year and immediate family rules seems to cover all contingencies at this point.
Not to be insensitive, but once someone passes away, their say in how things should be done here is over (that's for the realm of the living).
Also, my personal belief regarding all the living is that our judgements and opinions on things here are very likely to be altered after we have been deceased for a couple of years. What happens in the future if one of their deceased children decided that they wanted those ordinances? Should a decision by one of their relatives (e.g., a parent) made many years prior when they were still alive be binding on them in the hereafter? Should they be denied that work based on that decision by someone else so long ago by someone who (like all of us) has little real understanding of the eternities?
The 110 year rule with its associated "close relatives" rules covers all of these types of things. The need to document a person's wishes about them and their relative's ordinance work along with their vitals in this database are unnecessary IMHO.
Reference to D&C 132:7 7 And verily I say unto you, that the conditions of this law are these: All covenants, contracts, bonds, obligations, oaths, vows, performances, connections, associations, or expectations, that are not made and entered into and sealed by the Holy Spirit of promise,............are of no efficacy, virtue, or force in and after the resurrection from the dead;........
Ordinances apply only to Celestial Kingdom
Glad to help.
Your 1st cousin once removed is concerned about their self and immediate family. Since the 110 Year rule says that if you are not a member of that immediate family (or have not been given permission by someone in that immediate family), you cannot do the ordinance work for them. That would be how members of that family control whether or not ordinance work is done.
No need to document it as it is already under their direct control 😊