I haven't heard any consistent reports about steroids being a problem with LDN.....and I was subscribed to the LDN-Yahoo mailing list for a long time (had to unsubscribe because I'm not currently taking LDN, rather ULDN -- ultra low dose, micrograms rather than milligrams -- alongside pain meds to moderate tolerance and make it easier to taper off over the next few months in preparation for a "reset" that will let me try LDN this summer and if that doesn't work out, go back on pain meds while being able to take fullest advantage of the anti-tolerance adjuvants I'm using including ULDN, Memantine (Namenda), Dextromethorphan (DXM), Melatonin, Calcitonin, Lactoferrin, L-Theanine, Neurontin/Lyrica, etc because these work best at preventing the formation of tolerance rather than reversing it).
That's not to say that it isn't a problem, just that I haven't heard the number of reports about that which I would expect if it was a problem for everyone; I seem to recall having heard about lots of people who've taken them both and not had any clear issues with the combination.
I do know that some people have reported that thyroid issues can complicate the successful use of LDN....and sometimes steroids can affect the thyroid/adrenals....so that may be the connection.
Honestly, I think the only way to be sure about LDN is to try it, and that can involve being patient through a difficult adjustment period at first -- really you need 2-3 months to be sure how it's going to work for you long term, trying different dosages (some people can't tolerate more than 1mg, others do best on 4-5, etc....some have even tried doses as low as 0.1-0.5mg successfully) and giving your receptors/neurochemistry time to fully adjust after having been on traditional opiate agonist pain meds for a prolonged period....
You could theoretically also try ULDN with buprenorphine but I don't know of many reports of people doing that. One probably absorbs tiny amounts of naloxone from suboxone (as opposed to subutex obviously) so that could either be good or bad depending on your personal reaction to that combination, though there are distinct differences between naloxone and naltrexone, mainly that naltrexone lasts much longer, at least in the higher dosages. There is some debate as to how long naltrexone actually lasts in the low/ultra low dose ranges since there has been little hard research about this.
Going off the buprenorphine is one of the most difficult opioids to taper off because it is so potent in such teeny tiny doses (you're already taking 0.5mg/500mcg, so it's obviously difficult to accurately measure out smaller doses....though you could do it the same way I measure out ULDN, by dissolving a tablet in an exact volume of water, then measuring out a fraction of the water to get a known number of micrograms of buprenorphine), so doing that and eventually trying LDN would definitely be a considerable challenge -- but could be well worth it in the long run if LDN works for you.
I personally am going through hell and back to have the opportunity to try LDN, even though I think the chances are fairly good that it won't work out for me (though I'm doing my best to keep an open mind). If it does, the rewards are considerable....your own endogenous opioids (endorphins/enkephalins) are more potent than any exogenous opiate, have considerable health benefits, and will keep working indefinitely unlike exo-opiates which obviously have tremendous issues with tolerance and dependence. If you suddenly stop LDN, there is no apparent withdrawal, which surprises me but makes a certain degree of sense.
You didn't mention how long you've been on the bupe, but if it's only been a short time then you may adjust to it eventually and not have as many issues with sleepiness, constipation etc....still, if you're able to do the taper and take a few weeks to let your receptors adjust to being off exo-opiates, then go through the LDN adjustment period (start with as little as 0.1mg, ratchet up to 1mg, see how that goes, then trial doses up to about 4.5mg and go back down if you need to, then settle on whatever works best for you), the rewards are considerable.