I am a lefty, or actually a righty but I am left eye dominant so I have always shot guns, bows, and pool left handed.
I have owned, and still own, a lot of Browning BPS pumps over the last 40ish years, in large part due to the bottom eject. I can't do a cross face eject, it can just be a miserable experience. Granted, this is due to using a semi auto shotgun for bird hunting but I would occasionally get hit by residue coming out with the shell.
That said, I can operate a bolt fine whether it is RH or LH. I have a McM Game Hunter stock in a 30N with a right bolt. It was either get the gun well ahead of hunting season in RH or wait for a LH and get the rifle right before hunting season. I grew up shooting RH bolts so it wasn't a hard decision to get the rifle well ahead of the season even though it is a RH bolt. This is my elk gun, but some of the below could fill that need.
I have all my sporter style stocks in LH for the cheek piece, which I like to have for my deer rifles. I find it is hard to shoot LR for whitetails bc of the pop up blinds, stands, and box blinds make it hard to shoot much over 500 for me, and most whitetail is done inside of that anyway. And sporter type stocks are better all around as deer guns bc I rarely shoot deer prone. Here I have 2 280 AI's and a 30-06. I may rebarrel one of the 280's into a 6.5-284.
The exception to the above is my 11 yr old's 6.5cr. That thing is a joy to shoot and I need to do sight ins, figure out drops, load tweaking, etc, bc my son isn't quite ready for that stuff yet. It is a sporter stock with a cheek piece in RH stock and RH bolt. It is the most accurate gun I own, at least in my hands, so I can shoot it just fine. .3 MOA groups usually happen once or twice a range session.
I say all that to say that i have owned a random assortment of LH and RH bolt and stock combinations. I get the cross face thing, bc I hate it and can it make a hunt frustrating and/or miserable. But I have found that I can learn to operate a bolt well enough with a little practice. Follow up shots may not be quite as fast, but I have yet to come close to running into any issues. I can see how that may be something that folks would want to avoid but it is not a big deal for me. And bolt actions are simpler to reload for and more accurate, so my advice would be to get a LH bolt, and whatever issues he has can be overcome with practice - unless he needs a lightning fast follow up shot.