Version: 1.0.1
Forge: 12.17.0.1965

When mining a block and the repair happens during, the progress on mining said block is reset.

Unfortunately this isn't something I can fix, and the old Tinkers' Construct did this too. It's actually a fault on Minecraft's side, where it resets block break progress if the held ItemStack changes in any way (damage, quantity, etc.). Sorry, I've been using it in my single player and it's gotten me once or twice, but I find it mostly tolerable.

I never noticed it in 1.7.10, it gets me every few blocks

Just kidding. I've got releases out for all 3 MC versions now, currently being processed on CurseForge :)

Haha, good job.. && !player.isSwingInProgress ... seems simple enough :)

Just made a 1.7.10 pack with only tinkers in it. Created an obsidian level pick and used it for a while to get the durability down to like 400/700. I then placed a lot of obsidian on the grund, added a single moss and silky to it(to slow the mining speed to 5). I then proceeded to break the obsidian blocks (took about 12 seconds each), I broke 20 obsidian blocks without the progress resetting a single time.

Back in my 1.9.4 world with a mining speed 6 pick on 20 obsidian, it reset progress on me over 10 times. While some type of reflection code might not have been used in Tinkers' 1.7 to check if a player is actively destroying a block, and it may indeed have reset progress at times, it still remains a not obvious or annoying thing in 1.7.10. This auto repair makes mining blocks that take over a second an exercise in frustration.

Alright, I've got this fixed, I'll release an update for all MC versions tomorrow :)