Let's say I tweaked my node (or maybe it's part of an lnd release?) so that force-closes for HTLC timeouts only happen if it's "worth it". In this case, lnd would just fail the payment back to bfx-lnd0, and keep the channel open without the force-close dilemma described here (with the HTLC still pending).

Now, what if my peer is malicious and knows about (or at least assumes) my node's response to the timeout? They could reveal the preimage and claim the funds, effectively "stealing" (I'm not sure if it's real theft, hence the quotes) 11k sats from me. They could do this again and again, possibly hiding behind other pubkeys. Note that bfx-lnd0 would never give the funds to me, because I already failed the payment (and they failed it upstream towards the original sender).

There are tradeoffs, but I believe it's better to have a "it works 100%" atmosphere than "let's just hope my peer isn't a thief" kind of trust dilemma.

I did not tweak lnd, and the "safe" approach is the default. Right now I don't think there's an easy way to use the "unsafe-but-maybe-cheaper" approach.