I've always preferred horizontal dropouts with chain tugs for tensioning my chains,

because I've found that in order to get the most life out of a chain it's essential to be able to get the chain very tight and to be able to do it easily on the road (in case the chain starts getting thrown).

However, horizontal dropouts also create well-known problems with rear brake and shift cable (for IGH) adjustment. So I built a new bike with vertical/upward-facing dropouts:

and a telescoping bottom-bracket/crank-bracket to tension the chain:
telescoping_CB.jpg
And the best technique I've come up with so far for tensioning the chain with this configuration is to hold the front wheel with my knees, pull the BB with my right arm, and tighten the pinch clamps with my left arm. But although this seems to work as well as horizontal dropouts without chain tugs, I can't seem to tension the chain as tight or as precisely as I can with chain tugs.

Does anyone have any suggestions on possible techniques or methods I might be able to use to better tension the chain with the telescoping bottom-bracket/crank-bracket? What techniques do users of eccentric bottom brackets or eccentric hubs or other chain-tugless setups (who seem to face a similar problem) use?

The following are not solutions:
1. Idler: can't provide sufficient chain tension. Also the whole reason I ride SS/IGH bikes is because I can't stand the other compromises involved in using idlers.
2. Use body weight to press the rear wheel into a tensioned position: Not possible due to upward facing dropouts...gravity is working against me.

Thanks for your consideration. I'm cross posting this over in the Mechanics forum.