There is a caution to be remembered in this regard and it has to do with having two ATUs in the circuit.

A transceiver can be used barefoot through the LA-1K provided the external ATU (HF-AUTO or whatever) is the active ATU in order to protect the LA-1K.

There have been instances where hams have put their external ATU (HF-AUTO or whatever) in OFF or BYPASS, believing they could then use the transceiver's internal ATU to do the matching.

Paul warned against doing this in a similar discussion a year or so ago, and the caution is printed in the HF-AUTO manual:

Bypass mode bypasses the matching network.? Some users have the tuner in
Bypass allowing them to use their radio’s internal antenna tuner.? Caution is
needed in this last case if an amplifier is in the circuit and turned off or in bypass.
The standing waves (SWR) will potentially have high voltage nodes that can
cause damage to the bypass components in the amplifier.

In short, when operating a transceiver barefoot through the bypassed LA-1K, the operative ATU should remain the external ATU, not the transceiver's internal one (which should be disabled).

73,
Kent
K9ZTV