UPDATE — tried warming + icing:
Took the pen out 30 min early, iced the spot for 3 min before, injected slowly (held 10 seconds), iced for 5 min after, didn't rub.
Result: still got a small lump but it's maybe 60% smaller than usual and the redness cleared by day 2 instead of day 5. HUGE improvement!! Going to keep doing this. Thank you all so much 🙏