Original FSX addons compatible with FSX: SE?

I just needed an answer to this question of anyone could help. So I have been using flight sim ever since 2004 came out. And I've recently gotten back into it after not having a capable computer until now. And after getting FSX : Steam Edition a question came up. As for addons, there's an abundance of addons (payware specifically) that are geared towards the original FSX. I know that there's addons for FSX: SE but not as many as the original FSX. My question is, if I were to buy an Original FSX addon, would that addon work with the Steam Edition or is it not compatible? Thanks so much for the help!