On a weekday, the busiest time to see trains in the afternoon / evening between Framingham and Worcester is 6 pm and 10 pm.
B722 leaves Westboro and heads to Worcester, runs around its train usually between CP44 and CP45, then heads east on Tk 2,
switching at Sacks Whse (btwn CP39 and CP43) for about an hour, then switches the Grafton & Upton RR interchange, then Dana Films at CP33, then heads back to Framingham yard. Also in this time period, you will catch Q115, Q117, Q167, Q420 and
Amtk #448, the Boston section of the Lake Shore Limited. From time to time, other freight moves may take place on either track,
at any time, and in any direction. Commuter trains in this timeframe include 523, 527, 529, 533, 535, 536, 537.
In addition to the commuter trains and the westbound van trains, the Worcester area is usually pretty busy from 7 pm - 11 pm. Good chance of seeing Q427 off the B&M/Guilford/ST/PanAm/PAS (or whatever it will be called in the future) and Q426 going from CSX to the B&M at CP45. Also Q423 shoves out of the P&W at CP45 to go west on the B&A generally in this time frame.
Keep in mind that trackwork is currently going on at the west end of the B&A. This affects many of the "normal" train times on the east end of the B&A. Q421 and Q437 sometimes leave their origins (Boston and Framingham, respectively) in the afternoon. Even Amtrak passengers get to ride a bus between Boston and Albany 4 days a week due to the track work taking place that is right in the middle of when they would run.