Welcome to the site.
Well you see the concomitant use of Benzodiazepines such as Xanax with Suboxone is not absolutely contraindicated but it is considered very risky owing to their combination's propensity to cause respiratory depression which may thereby lead to coma and death.
So self administration of this combination is a strict NO at all times.
However if a situation reaches a point where these two drugs combination is inevitable and clinically important then you may use them in combination provided this being done under your doctor's prescription and guidance and regular monitoring of your vitals, plus the mildest dose of benzodiazepine ( 0.25-0.5 mg of Xanax if you that is what you want to use) is to be used to avert any sort of untoward side effect.
If it is only about insomnia then I will still suggest you to bypass the use of a risky drug like benzodoiazepine and instead make use of a typical and relatively safe sleep aiding drug like ambien cr (zolpidem) at dose of 6.25 -12.5 mg 1 hr prior to bedtime starting on the lower dose first.This is better and stronger than lunesta, so it may work for your insomnia.
Another safe alternative for your insomnia can be Benadryl syrup to be taken as 1 teaspoonful prior to bedtime, this will not only be a safe bet but also owing to it's sedative action it will help you to sleep better.
So kindly discuss these two alternatives with your doctor but if eventually you come around to try only benzodiazepine then you need to follow the strict guidelines and precautions as mentioned above.
I hope this helps.
Wish you all the best.
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