Simplifying.

@@ -25 +25 @@
-<s_inf>rarely used transitively; frequently used in the passive</s_inf>
+<s_inf>usu. in the passive</s_inf>

Google N-gram Corpus Counts
╭─ーーーー─┬────────┬───────╮
│ に報いる │ 51.638 │ 92.2% │
│ を報いる │  4.374 │  7.8% │
╰─ーーーー─┴────────┴───────╯
Google N-gram Corpus Counts
╭─ーーーーー─┬─────────┬───────╮
│ 報われる　 │ 207.251 │ 67.6% │Note that this is the 受身形 of 報う, but is commonly used as the 受身形 of 報いる (GendaiRK, Meikyo, GendaiSK)
│ 報いる　　 │  82.771 │ 27.0% │
│ 報う　　　 │   9.755 │  3.2% │
│ 報いられる │   6.695 │  2.2% │
╰─ーーーーー─┴─────────┴───────╯

BCCWJ:
｛に｝｛報いる｝：95
｛を｝｛報いる｝：3
Of those few transitive examples, all are for sense 2

Meikyo:
Has intransitive
Has this note on the second sense:
使い方：「旧敵に仇を報いる」 「一矢を報いる」 「恨みを報いる」など、他動詞としても使う。

Smk: （自他上一）〈だれ・なにニ━／だれニなにヲ━〉
Iwakoku, GendaiSK and Shinsen also have [vt,vi]


Nikkoku actually splits them:
Intransitive: sense 1
Transitive: sense 1 and sense 2 
Note: （２）「…をむくゆ」か「…にむくゆ」かについては、古く格助詞「を」をとっていたが、平安後期以降「に」をとるようになった。


There are plenty of examples of を報いる in the NDL, though it tends to be the second sense more often than it is the first from a quick glance
https://dl.ndl.go.jp/search/searchResult?accessRestrictions=internet&accessRestrictions=ooc&accessRestrictions=inlibrary&collection=A00001&collection=A00002&collection=A00022&collection=A00003&collection=A00014&collection=A00015&collection=A00188&collection=A00017&collection=A00016&collection=A00019&collection=A00121&collection=A00024&collection=A00152&collection=A00150&collection=A00173&collection=A00122&collection=A00162&collection=B00000&keyword=を報いる&fullText=true&eraType=AD&availableType=Persend&identifierItem=ISBN&includeVolumeNum=true&pageNum=0&pageSize=20&sortKey=SCORE&displayMode=list


.

Something should be done about this outlier case. Having no transitive tags isn't a great solution in my eyes.

I propose a version along these lines. Perhaps the note should also include something about the passive being very common

@@ -21,0 +22,4 @@
+<pos>&vt;</pos>
+<pos>&vi;</pos>
+<xref type="see" seq="2833992">報われる</xref>
+<s_inf>rarely used transitively; frequently used in the passive</s_inf>
@@ -27,0 +32,2 @@
+<pos>&vt;</pos>
+<pos>&vi;</pos>

Google N-gram Corpus Counts
82,771	 96.4%	報いる
   846	  1.0%	酬いる
 2,258	  2.6%	むくいる

@@ -11,0 +12 @@
+<ke_inf>&rK;</ke_inf>

ok