It says on the curse/curseforge page that HarvestFestival has CraftTweaker integration....
And yet the info needed to prove it has it, let alone to use this integration, is missing.

It wasn't me who wrote that. Don't know why Yulife decided that was a feature... Yes it has it. But I changed it a little that's why I didn't document it yet. Literally planning on doing that once I get todays release uploaded.

okay, thankyou.

I'll probably be adding Harvest Festival to my modpack.
I'll definitely be adding it to my pack if/when this feature I requested gets implement in some way, assuming I haven't added it yet by then.
#39

http://minetweaker3.powerofbytes.com/wiki/Mods:Harvest_Festival_Support#Shops

In 0.5.3 and below the shops one is replace Purchasable with Sellable so addSellable.

As for that #39 suggestion. If I am to do it. It would be a VERY long time off. I'm more interested in adding content than spending time on such things. You'll have to convince Girafi or someone else to do it if you want it sooner :P.