If you dont like the rp by sets what about a dropset 75 for as many reps as you can then immediately drop to 70 and keep going. It's harder on bench to do the drop unless you have a partner though who can switch you out. .
You can also get wrist weights to help with the increment. Cheaper than magnets.
Other alternatives is one day do the 70 lbs for higher reps and one day do the 75 for lower reps. Mix it up.
MTA: because it is rare I dont have more to say
"When I got too tired to run anymore I just pretended I wasnt tired and kept running anyway" - my daughter Age 7