The greatest strength of ElfDict is the cognates and words with similar meanings are very quick and easy to see. It's really handy when looking to find words for a concept, not a word-to-word translation. It means that you don't need to remember what exact word Tolkien listed the vocabulary with, and you can still find it. For translating, this website is super helpful!
It's also super friendly to newer translators who don't have a full grasp on the material yet. For my students, I often send them here because I know that they'll find it very easy to use.
There are a few weaknesses.
Sometimes, the mechanisms that make it possible to find cognates in other languages and similar meaning words are tricked, and you get a massive amount of information that has nothing to do with what you're looking for. The smaller the word, the worse the results are.
The outdated material can really mess up people who are new at translating. I think that you should remove the non-later material completely (like Qenya and Noldorin and Gnomish so on) and if applicable, use the updated/normalized/modernized versions of the words. Like, instead of listing Pelekta- as Qenya, list Pelehta as Neo-Quenya. You should update the warnings with links to articles explaining what exactly "Fan-invented" and "Updated" means and why using such vocab can be dangerous but also is the best option for filling vocab gaps.
Basically, I want to see you take this website in a different direction from Eldamo. Eldamo is a fantastic resource for scholars, for people who already know a lot about Tolkien's languages and are familiar with the lingo and conventions associated with it. Eldamo lists absolutely everything, with no filters except those that you place yourself. I think you need to focus ElfDict for a different audience. Make it more friendly for the newbies. This means less overwhelming amounts of information thrown at them at once, none of the older-languages, and basically a lot of hand-holding. I keep thinking back to Helge's Sindarin dictionary. It had plenty of flaws and is now quite outdated, but it was very very good at helping new translators navigate the translation world. I really liked that Nasal-Stop words were clearly marked and irregular plurals/conjugations were listed in the entry.
Basically, Eldamo is a descriptive resource, ElfDict needs to be a prescriptive resource.
I hope you find this helpful! Ar *estelyan i nál varna ar alwa sina morna lómesse.