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Current Transfer Ratio = current available through output device divided by input current through opto-diode.
Ahh, the opto..
Most are optimized and speced at 10 ma diode current. Yours is a little higher, but good. The 4N35 is a darlington so it has high transfer gain - 500% (5X) the diode current.
https://www.electro-tech-online.com/custompdfs/2013/03/4n32.pdf
So in your case with a diode current of about 15 ma. if you look at Fig 1 in the data-sheet the output will be saturated up to about 45ma of collector current - 15 ma diode I X 5(CTR) X .6 normalized for 15 ma. diode current. So you are ok with the values shown or you could drop the diode current a little so the micro doesn't have to work so hard.
PS. The 4N25 in your model is not a darlington so it may have a CTR as low as 25% so might look funny in your simulation.