An honest pool contractor would walk you through the pros and cons of both ways to address the pool’s chlorine needs…not fixate on one or another. As others have pointed out, a non explanatory “don’t recommend it” is suspect and should raise more red flags than a Chinese Red Square propaganda parade. It would make me reluctant to put much faith in any other replies to your questions.
If your happy to go the inconvenience of a DIY chlorine feeding routine or the cost of paying someone to do that, great. Alternatively, if you want an almost “set it and forget it” means of keeping that chem in line, and willing to incur minimal SWG cell maintenance and the arguably small risk of the SWG system going bad, than opt for a SWG system.
[I’m big time into convenience, which accounts for my having installed both a SWG system and a simple DIY acid chlorine system. Honestly , I don’t get why more savvy DIY chem maintenance members here don’t install an injector. It has a low difficulty installation curve …and plenty of posts here show how - mine among them. Did it years ago and never have had any issues..with PH levels always rock solid. ]