lr101 can't autofill both modes at once

[lpgagnon]

• Create a vessel with a tank and 2 LR101.
• Set one LR101 to tank-fed mode, one to pump-fed mode. Set tank to high-pressure.
• Open tank PAW, only one Fill: LR101 button is shown. Same in the Tank UI. Pressing it uses the pump-fed fuel mixture.

Workaround: detach one engine, fill tank, reattach. Tank-fed Autofill works fine when there's just one, tank-fed engine attached. Presumably the problem is when 2 parts use the same CONFIG but different SUBCONFIGs

Which mixture wins isn't consistent; appears to be 'first one attached wins' or something along those lines.

Probably a RealFuels limitation, but it's RO deciding to use a bimodal config for lr101, so logging here to begin with.