I see 3 search boxes for that page.
Summit search complete with an explanation. When I tried it with “Ben Nevis” it found 4 summits, 1 in Scotland, 2 in Australia and 1 in Arizona. Likewise when I entere “SS-001” it found 6 summits with that code. The results seem to match the explanation.
Distance Search with an explanation. Yes it failed for me with too many summits for 200km from my QTH. It fails for me at 65km. I don’t know what the best results for this function should be. I’m guessing there is a limit of 100 summits and that maybe an artificial limit or may be sensible. Perhaps a better result would be to the nearest 100 summits to a point? I don’t know how Jon’s algorithm works for this, it may only search the association the centre point lies within.
Search: The remaining search box searches the table of associations. It’s AJAX (if that is still the right term) so the page dynamically changes as you type. The search term is applied as a filter to the Association Code and Association Name columns. I hadn’t noticed this feature till you wrote about!
I can’t replicate that on Firefix Stewart. I clicked on LD-031 on SOTAwatch and it took me to the “new” summit page. I could see from the menu at the top it new I was logged in. Now I do have a window open to the Associations page having been testing Colin’s observations so maybe this is why it is different. I think this will always be a browser issue.