Im sure if your hack works, it could be tweaked to align with standards.. There are couple of changes I make upon loading a new snap.. Just been too lazy to work out the details of how to get them put into the code myself.
Someone had created a patch to get vnstat2 working, which I have to reapply on each new snap. Also I am not a fan of the local-ttl of 1 for dnsmasq.. I just don't see the reason to have such low ttl on my dns records.. They rarely if ever change, so I change it to 86400 in the services.inc file.
Would like to see this as option to set this to whatever you want, etc. Just too lazy to submit the code required to make it happen
I will get to it sooner or later.. But if you have worked out the changes required to give you a check box - seems you got most of the work done already.. Be a nice addition that multiple people might take advantage of.