Green Up in the Action menu

I am testing using green up from the action selection drop down when editing triggers, it does work but I would like to know why it doesn't bother sometimes. For example, lay at 3.8, place a back in the next round IF back has bigger oddds than the lay bet had BUT I notice if the next round back odds are high, 15.00 for example it doesn't place the back bet, what are its paramiters? can they be changed as sometimes the odds drop and the hand eventually wins and had it actually placed the back bet it would have a good return.

It can't place bet below the minimum:
Back £2 @ 15 -> Lay £7.89 @ 3.8
So to be able to greenup @ 15 your first lay bet must be greater than £7.89

OK, is there a way to tell it

IF back bet < minimum bet then

place back bet @ default back

Possible?

Yes (Settings -> Betting options -> Automatically adjust..) but in that case the proportion isn't correct for green-up

ok so if thats not possible how do you place a lay bet in round 1 then a back bet in round 2 against the same hand, how do you tell trigger to back against what it selected in round 1 if the price is > 10

I can't see a way to carry the selection through the next rounds

Any selection's Lay matched is greater than 0
AND fitting selection's Back price is greater than 10