not familiar with that one, but i am keeping c.petra for sev years now successfully, summer on the balcony, wintering indoors. i tent mine for winter xgiving to mar for many reasons, but it also mostly kept it clean of mites .
i killed a couple of crotons by spraying with hort.oil (in shade outside). though one of the florida outside growers said she uses it all the time without the problem. my guess, outside leaves are much tougher. i chanced it and plants dropped all leaves and died.
however neem oil is OK - i spray mine with neem periodically. i use bayer 'natria' brand 70% neem oil extract diluted for 'miticide application'.

What is your tent set up like? I have considered enclosing the crotons for humidity, but I was wondering if it might cause fungus/rot due to less ventilation.

I actually think it was an application of horticultural oil that killed my first croton too. I guess now I know to not try that again at least.

the set-up is very basic.
i just use huge 2'x4-5' dry-cleaners bags with a big hole up top and stuff a plant in each(plants are about 3' high) - they are under the shelf, but get sideways some dappled sun in west-NW corner window mid-day only 2-3 hours. but there is never any condensation - so my leaves are touching plastic always, but i never had a problem with that.
i water-wick them from the bottom.i do allow them to dry up somewhat before i refill the reservoir.
tenting keeps them warmer and they get quite toasty on sunny days, may be to 70F? (temps by the window drop to 58-62F at nite), so they will be taking up water.
however if your temps are lower then this and you have lower light levels, you'll need to keep them drier at the roots, but still tenting should will be OK.
mine maintain their leaves, hardly any dropped. they are still bagged for a couple of weeks (we are getting 20-25F at nite here). one has been flowering for a month now (in the bag ;)).
you could set-up even larger enclosure: the film-sheets for insulating windows are very good - tape them and you can get a very large bag - connect to shelves/posts/over horizontal pole, even with some long stakes will work.
it would look silly in the living room, but of course mine are in the spare bedroom out of sight :).
some sort of industrial shelving with just a few wire shelves can be used draped with window film as a huge cage.
when i checked a month ago - they were clean. when i checked just now i saw some mites here'n there. not much, but they usually appear out of nowhere when it gets really sunny and warm - i've been getting full blast noon to sunrise sun a couple days a week for a few weeks in that room. need to spray now.

Thanks for the advice. Glad to hear that seems to be working for you! I'm going to try some enclosures while it is acclimating at least

I've grown a number of colorful Crotons indoors (not this one) & kept them all on humidity trays, never had any insect problems at all.

Crotons are pretty thirsty plants, I thought Spider Mites came around to very dry plants. Perhaps keep it better watered, on a humidity tray & you won't have the problem.