Applied by tools/build_hactool.py to SciresM/hactool (ISC) at 1d64a83450e025622f3468c28fc4164dad2c5ef6.
From MacNativeGames build_app.py build_hactool() (MIT, Copyright (c) 2026 MacNativeGames contributors), the parts
that run on Windows: MNG_TITLE_KEYS names the title-key file, and the BKTR checks accept the subsection table
padding and the subsection layout of newer cumulative updates. Its funopen base-range hook is macOS-only and left out.

diff --git a/main.c b/main.c
index 07f53cb..7921cc4 100644
--- a/main.c
+++ b/main.c
@@ -472,7 +472,7 @@ int main(int argc, char **argv) {
     }
 
     /* Try to load titlekeys. */
-    FILE *titlekeyfile = open_key_file("title");
+    FILE *titlekeyfile = getenv("MNG_TITLE_KEYS") ? fopen(getenv("MNG_TITLE_KEYS"), "rb") : open_key_file("title");
     if (titlekeyfile != NULL) {
         extkeys_parse_titlekeys(&tool_ctx.settings, titlekeyfile);
     }
diff --git a/nca.c b/nca.c
index 8a84366..2fe877f 100644
--- a/nca.c
+++ b/nca.c
@@ -1149,7 +1149,8 @@ void nca_process_bktr_section(nca_section_ctx_t *ctx) {
     /* Validate magics. */
     if (sb->relocation_header.magic == MAGIC_BKTR && sb->subsection_header.magic == MAGIC_BKTR) {
         if (sb->relocation_header.offset + sb->relocation_header.size != sb->subsection_header.offset ||
-            sb->subsection_header.offset + sb->subsection_header.size != ctx->size) {
+            sb->subsection_header.offset + sb->subsection_header.size > ctx->size ||
+            (ctx->size - (sb->subsection_header.offset + sb->subsection_header.size)) % 0x200 != 0) {
             fprintf(stderr, "Invalid BKTR layout!\n");
             exit(EXIT_FAILURE);
         }
@@ -1180,7 +1181,9 @@ void nca_process_bktr_section(nca_section_ctx_t *ctx) {
         ctx->bktr_ctx.relocation_block = relocs;
         ctx->bktr_ctx.subsection_block = subs;
 
-        if (ctx->bktr_ctx.subsection_block->total_size != sb->subsection_header.offset) {
+        if (ctx->bktr_ctx.subsection_block->total_size != sb->subsection_header.offset &&
+            (sb->relocation_header.size > sb->subsection_header.offset ||
+             ctx->bktr_ctx.subsection_block->total_size != sb->subsection_header.offset - sb->relocation_header.size)) {
             free(relocs);
             free(subs);
             ctx->bktr_ctx.relocation_block = NULL;