I'm also interested to hear...

Tipweight might not be necessary - the upper cylinder and tank are outboard of the model's centerline, no? Spiderwire lines are nearly weightless, too.

Tipweight may be another thing I've overthought (?) (Much of my Army career was in places where opportunities to fly weren't frequent. I could think about and try to understand things. I got more benefit in the infrequent flying opportunities ...And I could to test ideas. Many didn't work, or were more effort than they were worth. What I offer is what did work well.)

You can 'pre-set' tipweight to balance line weight without numbers. This works best for larger models, tho, as you are likely to have a spare empty reel around, and an idea of your flying lines length and diameter (An empty spare reel is used to balance the weight of the reel with the lines on it.)

So, turn the model upside down on a level surface so it can rock on the fuse top and rudder. Put the reel with lines centered halfway from the fuse center to the leadout guides. Center the spare, identical empty reel the same distance from the fuselage center on the outboard wing. Match any line clips or connectors side-to-side too.

If the inboard wingtip sinks to the table surface, add weight at the outboard wingtip until it is close to balanced, or very slightly outboard heavy.

The principle - As the model flies fairly low and level, we carry half the line weight at the handle. The inboard wing's line guides support the other half. It's the big kid-small kid seesaw situation.

Half the line weight at full distance matches full line weight at half distance. If the model balances on its centerline in flight, it will not tend to roll inward due to line weight.

CL models usually need tipweight weight to balance the half of line weight carried at the leadout guides. But, I did have a very light, small .15 profile where the engine and tank overbalanced line weight. A small amount of weight in the inboard tip balanced the model - it flew great. This is rare, though.

This works best for fairly low level flight. Our stunt maneuvers change the strength and directions of many forces in very brief time. CL models fly and maneuver upright and inverted - "insides" and "outsides" - equally. Balancing line weight as above sets your model at the center of the range of those changing forces.They vary equally both ways from neutral level flight.

(Again, this is not precisely accurate, but very close for practical purposes. It does work well, dependably.)