Just an update after close to a year. My personal impression from #mirc channels is this change seems to have had a positive effect. As in, it appears that there are fewer people complaining about losing mirc.ini than before. Of course this is not exactly a reliable statistic, but it's something.
However, it also appears that the issue is not entirely resolved yet. With the newer mIRC versions, so far I've seen two people report loss of mirc.ini after a power failure, with (as far as I can tell) very regular system and mIRC setups and thus no other probable explanation.
As such, it might still be worth trying slightly heavier ways to preserve mirc.ini, or at the very least printing some information that may help identify the root cause. For example, if mirc.ini cannot be loaded but the default directory contains other mirc-generated files that are never installed by default (is remote.ini among those?), print some information about why mirc.ini couldn't be loaded (missing/empty/corrupted) or so. After all, with the new situation, in theory mirc.ini should never be lost. Anyway that's my 2c..