diff --git a/piker/tsp/__init__.py b/piker/tsp/__init__.py
index adbe484e..1eac1c66 100644
--- a/piker/tsp/__init__.py
+++ b/piker/tsp/__init__.py
@@ -458,13 +458,15 @@ async def start_backfill(
                     'bf_until <- last_start_dt:\n'
                     f'{backfill_until_dt} <- {last_start_dt}\n'
                 )
-
-                # ugh, what's a better way?
-                # TODO: fwiw, we probably want a way to signal a throttle
-                # condition (eg. with ib) so that we can halt the
-                # request loop until the condition is resolved?
-                if timeframe > 1:
-                    await tractor.pause()
+                # UGH: what's a better way?
+                # TODO: backends are responsible for being correct on
+                # this right!?
+                # -[ ] in the `ib` case we could maybe offer some way
+                #     to halt the request loop until the condition is
+                #     resolved or should the backend be entirely in
+                #     charge of solving such faults? yes, right?
+                # if timeframe > 1:
+                #     await tractor.pause()
                 return
 
             assert (
@@ -572,15 +574,19 @@ async def start_backfill(
                     f'{next_start_dt} -> {last_start_dt}'
                 )
 
-                # always drop the src asset token for
+                # NOTE, always drop the src asset token for
                 # non-currency-pair like market types (for now)
+                #
+                # THAT IS, for now our table key schema is NOT
+                # including the dst[/src] source asset token. SO,
+                # 'tsla.nasdaq.ib' over 'tsla/usd.nasdaq.ib' for
+                # historical reasons ONLY.
                 if mkt.dst.atype not in {
                     'crypto',
                     'crypto_currency',
                     'fiat',  # a "forex pair"
+                    'perpetual_future',  # stupid "perps" from cex land
                 }:
-                    # for now, our table key schema is not including
-                    # the dst[/src] source asset token.
                     col_sym_key: str = mkt.get_fqme(
                         delim_char='',
                         without_src=True,