I must have a decent worm as with polar alignment i can hold round stars for close to 3 min and out of 10 shots i keep 7-8 of them. But still if your PE is that bad that you need an PE program to give the guider a chance, take it back or upgrade the worm gears.
You are right with the Meade 10" but then again im running 25kg of telescope optice/gear on a EQ 6 with a 2x 2" barlow putting the F# at 9.2 and still get round stars with a rough polar align. When guiding came to sub pixel then as long as it was close enough aka polar and PE, it negated most of it. Im not saying that with the incresed accuracy (minimized) of PE and 10 min no drift Polar your guider would be doing little work, but once again if your cam can do .5 second iterations and shoot the guiding command though eqmod/ST4 port in less than a second you will always get round stars
As with everything there is a limit to accuracy with atmospheric turbulence, light pollution, and pollution in general if your looking for that Nth degree of accuracy go into the darkest spot you can find, and wait for that perfect night where the atmosphere is still
then all the fine fine adjustments and perfect PE will make the difference between a good shot and a unreal shot
(don't miss understand me i just love debating and will push my point till somebody can prove to me without a doubt that their way is better for me than my way
as everybodys way works best for them as it is what they are used to)