Well good question. The stocks we currently have since just got this Mill in the spring of 2021, are just under 19" for the action and barrel channel so not a problem. (McMillan XIT). I don't foresee any issue with a longer stock and flipping it. With the DRO it is easy to set up. For the price we paid and what we need it for we liked this one for the options it has. To get a few inches more travel is almost double todays price for a new Griz Mill. I am sure that if you look at Used equipment sites you can possibly find an older SB, Bridgeport that may be old, but in great working condition. I missed out on some deals where the Mill, Lathe looked beat, but only cosmetics. New Paint job and cleaning saved you $$$$.
We bought this model G0759 last year for around $2,300 to the door. Got a great deal from Griz.
This model now is a little over $3,195 (- 5% sale) + $189 ship & Tax from Griz.
US Tool Depot has the same price but talk to Chris Stone-Owner and he may give you a deal and no tax. If you need any equipment, try them. We bought several lathes and saws from US Tool. Excellent customer service.
If you have other questions send me a PM and we can talk.
Thanks
Len