It is the last Trampoline Forwarder that should be checked, not the
first one.
Consider route (of Trampolines only):
Alice-electrum -> T_ACINQ -> T_Hodlister -> Bob-electrum
Even if Bob has a transport open with ACINQ or even if Bob has a channel open with ACINQ,
Alice can safely use end-to-end trampoline for this route: ACINQ will not know who
the recipient is, so they will not try to do pay-to-open (and hold up the payment for minutes...).
related: https://github.com/ACINQ/lightning-kmp/pull/237
04bc7fd28f