I believe that if you are truly worried about fatigue during a match affecting the feel of a cue in your hands then the cue balance would be more important than a half ounce or so of weight. Most cues today fall between 18.5 and 19.5 in weight and most are not heavily rear weighted cues.
In the pre 1980s, cues would more often could be weighted 20 to 22 ounces and be much more heavily rear weighted, thus, "rear balanced". Those older cues may cause the cue tip to rise a bit too much during the final stroke as one tired and the rear weight pulled down against a tiring forearm muscle.
With your concerns, I would say strive for a neutral to slightly forward balanced cue that is comfortable to you and not much more than the 19 ounce range.
My personal choice is a very neutral balance to slight forward balance - I find that a cue in my hands that I am least aware of is the best cue for me- I don't like the cue to pull too much in one direction or another. When a cue feels like that to me, I can go on playing forever
Some cue makers do not use weight bolts at all - like Mike Capone ( his cues tend to play in a more neutral balance zone). Some of the newer cue companies use a very adjustable weight "system"- you may want to investigate those options as well.