Our society, in general, has become much more aware of the sensitivity of some individuals to strong scents just as it has to peanut and other allergies.
I know that scents can be a problem in church for some people, especially those with breathing difficulties. Sometimes, the structure of the church adds to the cause. In a building with low ceilings where incense smoke and other strong scents have no place to dissipate, I have noticed it is worse than in churches with higher ceilings.
We first have to understand and accept that this can happen and then find solutions that will help people to be able to worship without choking.
For intolerance to incense, I know of priests who have found ways to minimize the difficulties.
One announces in the bulletin the Sunday before major feasts at which Mass incense will be used. This allows people the choice of coming to another Mass.
One lets people know before the incensing at the Mass so they can move further away from the altar where incensing usually takes place. Others have probably come up with other solutions.
I know of people who take their place as far as they can from the altar or near a door so they can move out if they have problems.
Excessively strong perfume is another story. People who like strong scents often don't even think of the possibility of others being bothered by them. Because we live in a society where smelling good is just as important as dressing well, people have to be alerted to the problem they can create.
In a controlled atmosphere such as a church, I believe it should be simple enough to publish in the bulletin that people should exercise restraint in their use of perfumes because they sit so close to one another.
It should also be announced because not all people take bulletins home to read. Even among those who do, the hustle and bustle of family can easily cause them to misplace a piece of paper.
If there are continued repeat offenders, it should be brought up to them privately as they may not have fully understood the impact of their practice.
Having brought this subject into the open, your question may alert priests, parish staff, parish councils and others to the importance of this issue.
Everyone should be comfortable enough in church to be able to keep their attention on the Mass and not on physically surviving the assault to their senses. This is simple Christian charity.