i use this

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i do not use it on large issues. but on games with a heavy grain, it levels out the grain nicely once sanded. after i sand it i put down my coat or two of sanding sealer then it is smooth as a glass. i still use bondo on large issues and holes but this is what i use on grain issues. the benefit is this is easier to sand and holds better on spots that bondo tends to not hold well like very thin layers.
it also makes a stronger corner than bondo. i have had bondo chip off corners but this stuff is tougher IMO

it has two parts like bondo so your working time can be adjusted a little by cutting back on the activator a little. but that is only a little. to little activator and it will not harden to much and you have little to no working time. i just do small sections at a time.
never used that quick wood but i do use this one.

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