Hi Paul,
I've been using Maxim for a long time for both acquisition and guiding.
IMO it has a lot more control than most out there.
I pretty much leave the advance settings these days to default. Use fine aggression control in the main window.
While every mounts response will be different depending on the speed of relays/ guider interfaces and ports, I use around 6.6 in Ra and Dec using 3 sec exposures. Robins around the same mark, at least on a ball park setting.
I found binning the guide camera made guiding so much more efficient.
A thing to watch, as you've been doing is the corrections. Make sure it's not too aggressive and over shoot. So a big jump from - to + will indicate this unless it's a shocker of a night and you're on a faint guide star.
Keep watching the accumulative guide error with the graph... of course lower the better... but this will take a little time to fine tune your aggression settings that will work for you. Too harsh a setting, getting up over 7 will basically be chasing the seeing and really take away control from a well behaved mount
Also when
just calibrating, (I select my own when guiding for imaging) let maxim find its own guide star (just select calibrate) I've found this works best. If you find calibration is not working, (ie guider moved <5 message) increase the calibration time up to 20. This has always worked for me.
If you have pulse guide with your PME, turn it off on your mount control while calibrating as this causes all sorts of weird stuff to happen.
Other than that, all trial and error as long as you have the basics down.
I've been doing exactly the same thing last night myself with my new SX OAG... certainly nice to see the stars in the same place without drift anymore

, and 8min subs, yea haaa.. this is the way to go for sure!
Now for a decent night..
Hope this will help a little and plus reinforce what you're already doing.
Rich