diff --git a/src/schema/rules/checks/dwi.yaml b/src/schema/rules/checks/dwi.yaml
index 4183c51e74..d0b71d9a2a 100644
--- a/src/schema/rules/checks/dwi.yaml
+++ b/src/schema/rules/checks/dwi.yaml
@@ -41,7 +41,7 @@ DWIBvecRows:
     - suffix == "dwi"
     - '"bvec" in associations'
   checks:
-    - associations.bvec.n_rows == 1
+    - associations.bvec.n_rows == 3
 
 # 32
 DWIMissingBvec:
diff --git a/src/schema/rules/checks/nirs.yaml b/src/schema/rules/checks/nirs.yaml
index c6b8f74548..3ec07ce1d2 100644
--- a/src/schema/rules/checks/nirs.yaml
+++ b/src/schema/rules/checks/nirs.yaml
@@ -23,24 +23,28 @@ NIRSChannelCount:
 ACCELChannelCountReq:
   selectors:
     - suffix == "nirs"
+    - count(associations.channels.type, "ACCEL") > 0
   checks:
     - sidecar.ACCELChannelCount == count(associations.channels.type, "ACCEL")
 
 GYROChannelCountReq:
   selectors:
     - suffix == "nirs"
+    - count(associations.channels.type, "GYRO") > 0
   checks:
     - sidecar.GYROChannelCount == count(associations.channels.type, "GYRO")
 
 MAGNChannelCountReq:
   selectors:
     - suffix == "nirs"
+    - count(associations.channels.type, "MAGN") > 0
   checks:
     - sidecar.MAGNChannelCount == count(associations.channels.type, "MAGN")
 
 ShortChannelCountReq:
   selectors:
     - suffix == "nirs"
+    - '"ShortChannelCount" in sidecar'
   checks:
     - sidecar.ShortChannelCount == count(associations.channels.short_channel, "true")
 
@@ -53,11 +57,15 @@ Component:
   checks:
     - columns.component != null
 
-RequiredChannels:
+RecommendedChannels:
+  issue:
+    code: NIRS_RECOMMENDED_CHANNELS
+    message: |
+      NIRS files SHOULD have an associated channels.tsv file.
+    level: warning
   selectors:
-    - datatype == "nirs"
-    - suffix == "optodes"
-    - extension == ".tsv"
+    - suffix == "nirs"
+    - extension == ".snirf"
   checks:
     - associations.channels != null
 
diff --git a/src/schema/rules/sidecars/nirs.yaml b/src/schema/rules/sidecars/nirs.yaml
index 4870887c23..de84a85536 100644
--- a/src/schema/rules/sidecars/nirs.yaml
+++ b/src/schema/rules/sidecars/nirs.yaml
@@ -149,7 +149,7 @@ NirsRequired:
     # Following counts required conditions enforced in checks
     ACCELChannelCount:
       level: optional
-      level_addendum: required if any channel type is ACC
+      level_addendum: required if any channel type is ACCEL
     GYROChannelCount:
       level: optional
       level_addendum: required if any channel type is GYRO