%2003_added%
%2003_first_played%
%2003_last_played%
%2003_playcount%
%2003_loved% (1 or blank)
%2003_rating% (up to 10 via the context menu)

%2003_now%
%2003_added%
%2003_first_played%
%2003_last_played%

%2003_now_ts%
%2003_added_ts%
%2003_first_played_ts%
%2003_last_played_ts%

%2003_playcount%
%2003_loved%
%2003_rating%

$select($add(%FEEDBACK%,2),X,,❤)

$puts(t,$select($add(%FEEDBACK%,2),$rgb(0,0,0),,$rgb(255,34,34)))
$set_style(text,$get(t),$get(t))

It think only timestamps is good enough, since the dates can be easily converted in JS anyway, so I don't see it as a loss.
Having the possibility to get all timestamps for JS and single first/last value for TF is perfect.

$jsp3_since is exclusive to the title format functions in that component. It's not possible to make them globally available.

I suppose another %2003_something% field could yield the same result if I hardcoded the input to just last played. I'll think about it.

%2003_plays_prev_year% GREATER 10 AND %2003_rating% GREATER 5 SORTED DESCENDING BY %2003_plays_prev_year%

Obviously it would be interesting to be able to do that via TF for any year

var tfo_id = fb.TitleFormat("%path%|%subsong%");
var tfo_lastfm = fb.TitleFormat("%lastfm_played_times_js%");

var items = plman.GetPlaylistItems(plman.ActivePlaylist);

var dump = [];
for (var i = 0; i < items.Count; i++) {
	var item = items.GetItem(i); // GetItem is JSP3 only, SMP uses items[i]
	
	var arr = JSON.parse(tfo_lastfm.EvalWithMetadb(item)).map(function (item) {
		// foo_enhanced_playcount uses JS timestamps with millisecond accuracy, we don't want that
		return item / 1000;
	});
	
	var obj = {
		"id" : tfo_id.EvalWithMetadb(item),
		"2003_plays" : arr,
	};

	dump.push(obj);
}

var str = JSON.stringify(dump);
// can't remember if SMP writes BOM by default or not?????? It has to be disabled. JSP3 does not write BOM at all
utils.WriteTextFile("z:\\dump.json", str); 

$substr(%2003_added_ago%,0,$strstr(%2003_added_ago%,d))