I'm not sure I'm an expert but I have tried the absolute hell out of it & can speak from experience I guess (there are some in this forum that know the industry inside out so can probably speak on this in way more depth than me). I guess the reason it's not discussed on PL is because this place is for punters in essence... arbing isn't punting I don't think (more trading really), probably more suitable forums about, though happy to give a few brief thoughts (apologies if all very basic & well understood by all anyway).
My experience is purely from a punter-trying-to-beat-the-bookie perspective, I've never worked at/ traded for a bookie. In short: punters need to represent value to the bookie, if you can't do this, you're not worth having around. Every account is assigned a score, if you heat that score up by placing bets beyond the market all the time the time you'll show up pretty quickly & they'll jump on you. Long-story-short, if you try to beat the bookie through arbing, as in going for it to the max daily , race after race, as a punter, this will be seen within days, sometimes sooner, & your account will be shuttered because you are taking value from the bookie, i.e. you are doing what they do.
Personal view, speaking from experience here, it's not actually worth it as a punter to get shuttered by the big firms coz they give the best prices & freebies tbh. Could probably get away with the odd big arb on a big football match (so there's plenty of liquidity on the exchanges) where there's been a clear misprice but you need to be quick with the lay (as there are plenty in the market trying this & the likes of Oddsmonkey have the tech to show the gaps as soon as events are priced up by the bookies) & have plenty of capital on hand.... not worth the effort as you have to be hitting the sh1t out of every gap to make anything half-decent so it's a drain on your time too. Honestly, as a punter, you are better off opening many many bookie accounts (something I was late to myself) & taking all the bet boosts & free bets on offer.