I guess by now you’ve tried a few things. Let us know what worked or didn’t work for you…
Hardly any Beeminder goals actually require daily entry – the commitment can be expressed in terms of a daily average rate, but if you do ‘enough’ once a week, that’ll see you through to the following week.
For me, when I measure fitness goals, I never want to be in a situation where I cause myself injury in the name of following a set program. Particularly with weights, I’d want to allow myself to ‘stall’ or even de-load in order to make more long term gains.
So I’d probably set this up as a goal to do my routine, properly and safely, three times a week. Even though the routine has to do with increasing the weight I can ultimately lift, that’d be a do more goal type.
Which is pretty much what you described, but instead of entering your current bench press, you’d just enter a one (1) to say that you followed the routine that day, and maybe put the current weight in the comment field.
(There’s an advanced feature that would let you enter the weight in the datapoint field and it’ll update the graph as though it’s a one. Not accessible to everybody though, and not hugely user friendly.)
In addition to a goal that focusses on the bench press, I’d probably also create one that’s about following my chosen program, and one that’s about improving my flexibility/mobility. All of those are likely to be ‘do more’ goals with a commitment of a few times each week.
If I didn’t have anywhere else to see the progression in weight, I might also create an almost-flat goal so that I could see that graph too. But I wouldn’t commit myself to anything aggressive on that, because it should be a result of doing other things that are more enforceable. Generally speaking, beemind the inputs rather than the outputs.