user4334: According to this, the BIP 148 UASF (user activated soft fork) goes into effect on August 1. Supposing it results in a substantial fork in the blockchain, is there a way users of Bitcoin Core can choose which chain to use (as opposed to whichever chain one's node receives first)? In other words: How do I tell Bitcoin Core to use an alternative chain?
Is this what preciousblock* is for?
*"Treats a block as if it were received before others with the same work."

user5406: From what you linked it seems to me that preciousblock doesn't supersede a longer chain, it just prioritizes one block over another at the same height.
You could call bitcoin-cli invalidateblock <blockhash> on the first block of the chain that you wish not to follow.

4334: <p>According to <a href="https://bitcoinmagazine.com/articles/bitcoin-beginners-guide-surviving-bip-148-uasf/#1496254102" rel="nofollow noreferrer">this</a>, the <a href="https://github.com/bitcoin/bips/blob/master/bip-0148.mediawiki" rel="nofollow noreferrer">BIP 148</a> UASF (user activated soft fork) goes into effect on August 1. Supposing it results in a substantial fork in the blockchain, is there a way users of Bitcoin Core can choose which chain to use (as opposed to whichever chain one's node receives first)? In other words: How do I tell Bitcoin Core to use an alternative chain?</p>

<p>Is this what <a href="https://bitcoin.org/en/developer-reference#preciousblock" rel="nofollow noreferrer"><code>preciousblock</code></a>* is for?</p>

<p><sup>*"Treats a block as if it were received before others with the same work."</sup></p>
 5406: <p>From what you linked it seems to me that <code>preciousblock</code> doesn't supersede a longer chain, it just prioritizes one block over another at the same height.</p>

<p>You could call <code>bitcoin-cli invalidateblock &lt;blockhash&gt;</code> on the first block of the chain that you wish not to follow.</p>
