Those of you who play mono records cut back in the hey day when that was the only format but today reissue producers don’t want to try and sell records that customers have to jump through hoops to play them back properly. Mono reissues are at a marketing disadvantage already just because they’re mono.
The only reconfiguring they might do is and probably electronically, is to limit the cutting head’s movements lateral only to reduce noise and keep in check out of phase anomalies if they were to occur, its the same stylus profile, geometry etc.
The advantage to using your preamps mono switch is to cancel the surface noise picked by your stereo cartridges vertical motion (the opposite stereo channel) and most reissue vinyl is so meticulously pressed these days that it’s free of surface noise most of the time anyway and can be played just fine with systems that lack the ability to combine the channels. Oh, don’t tell me about that $20 repress you bought that was mastered from a dubiously disclosed source mastered and pressed who knows where! Believe what you want though if it makes you feel better.