The ability to mark locations when using the spyglass is very useful, particularly when doing Bastilles of Intellect. I use it to mark pillars and then commit to memory the order using the symbols as reference. I find that MUCH easier than trying to remember the order at the larger Bastille's of Intellect without the symbols.
The thing is, the bastilles can have up to 7 pillars but the Spyglass only has 5 marking symbols. While not a huge deal, I think it would still be quite useful if the spyglass had at least 7 different marking symbols.
and with this request I learned that the spyglass can mark things in the first place! and I agree it should at least have as many options as there are pillars.