Be Careful What You Wish For
Republicans in Georgia liked democratic legitimacy until they started losing elections again. As soon as metro collar counties like Gwinnett, Cobb, Douglas and Henry started turning purple and blue and they started losing local elections, they began questioning the wisdom of local control and partisan elections. The first major assault was on elected District Attorneys. About ten years ago they cooked up a plan in Douglas County whereby the incumbent (Republican DA) could resign at the perfect time thus cancelling the election and allowing the governor to appoint a new DA and reset the clock on the new election - just like in judicial races (something that's sadly written into the Constitution). They even did it twice! Finally, after they tried to do it in Clarke/Oconee Democrats got wise to the actual wording of the Constitution which said DA's "shall" be elected every four years and the state Supreme Court shut down this scheme.
Now places like Douglas and Athens have left leaning DA's and Republican officeholders like Rep. Houston Gaines (R - Athens, but only thanks to gerrymandered voters who want nothing to do with Athens) are upset about it and looking for ways to improve on the wisdom of one person / one vote. In Gaines's case, that means new laws trying to force the DA to behave more to his liking or even splitting that circuit so that more Republican Oconee can get it's own DA and judges (side note - can we talk about Oconee - Georgia's highest college educated county but still stubbornly Republican?)
Other cases of tampering can be found in the ongoing redistricting drama in Cobb where the Democratic majority local commission is asserting its home rule right to draw it's own map over the gerrymandered map foisted on it by the Republican legislative majority from outside of Cobb, and most recently in HB 48 which would convert all DA and solicitor elections to non-partisan elections held during the primary instead of the general.
The main sponsors on this bill come from greater Savannah and the next frontier of metro collar counties like Paulding and Carroll. Presumably they like the math of a primary when Republicans typically outvote their Democratic peers by as much as 20-40%. Take Gwinnett - essentially a reliably blue 60/40 Dem county in general elections, Republicans outvoted Democrats 52-48 in the most recent primary. Blueing Paulding may vote for a Democrat in a general election sometime this decade, but will presumably stay red on primary day much longer. And places like Savannah, Augusta, Macon and Columbus once had a more "stable" status-quo that conservative whites essentially controlled but in recent years have been behaving more like partisan Democratic places on the local level.
Well, if the voters don't behave the way Republicans want them to, they must not know better anymore! So, why do I say be careful what you wish for? It's not just because every election change made to benefit a party typically backfires (hello Sen. Ossoff and the entire Biden agenda, who would have lost outright under the old 45% plurality no-runoff rule).
It's also because Democratic voters in Fulton and other places like Gwinnett have gotten wise to voting around non-partisan races designed to disenfranchise them - strategically voting for women with "black" names to boot out white Republican appointed incumbents even with little paid communication telling them who was who.
It's also that increasing education polarization means that the primary vote advantage that Republicans once enjoyed is slowly withering away. Case in point, '22 and '14 had very similar primary dynamics, with competitive Sen/Gov on the R side and token Sen and uncontested Gov on the D side. In 2014, Republican primary ballots were 65% of the total, in 2022 Republican ballots were only 62% of the total. And there is a lot of evidence that as many as 80k of the Republican ballots were Democratic crossover voters voting pro-Kemp/Raffensperger and anti-Perdue/Walker/Hice, if the 80k number is right, the Republican edge whittled all the way down to 58%. You can call a race non-partisan, but highly educated (and increasingly Democratic leaning) voters will figure out who is who.
But finally - be careful what you wish for because eventually the Guy Millner curse will be over and there will be a Democratic Governor making vacant appointments. Republicans are going to trade having a few more years of a Republican DA in one or two metro jurisdictions for many future stealth Democratic appointments in red Georgia for generations.
Again, be careful what you wish for! And even though I think this would benefit Democrats over the long term, I'd still be opposed to it because I think the voters should decide, and they decide better in important races like these when they have more information (which party someone is).