Are annual systemic insecticides and funguscide treatments a good idea on JM's? If so, how often would you do it?
What's your purpose for wanting to use them? Do you have insect/fungal problems with your trees? Generally the use of any pesticide is not warranted or recommended unless there is a specific need for it.
FWIW, I've never used any pesticide in any form on any of my maple collection, either in-ground or in containers. What few aphids that may appear in early spring get washed off with a strong spray of water only.
I don't necessarily want to use it but I have some. I wasn't sure if the pros outweighed the cons, etc. In most others things I have done, preventative maint. is a good thing. Trees are still fairly new to me so I am asking every question I can think of. How about funguscide use in low dose as a precaution?
Current recommendations are to protect the environment and yourself by treating only when needed.
Preventive treatments are seldom done except for dormant sprays on fruit trees.