Varroa sublimation advice

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Hi, decided to give 3x'OA' sublimation try for the first time, on a colony I had concerns about re varroa drops vs others in same apiary. Dates were as follows:

A consistent drop of 5 / 6 varroa per week from Jan to mid Feb (previously had Apivar treatment Sept/ Oct, then one vap. early Dec). All other colonies in same apiary had max 0 or 1 mite drop per week during the same period & continue at a v low level since.

Gave 3 vaps to the colony of concern on 21/2; 26/2 and 3/3 i.e. 5 days apart

Drop since:
21/2-26/2 = 6 mites
26/2 -3/3 = 2 mites
3/3 - 8/3 = 6 mites
8/3- 15/3 = 1 mite
15/3-24/3 = 1 mite
This seemed v low given the history of 5 or 6 mites drop per week pre treatment but pleased post treatment a low drop for a couple of weeks. Noticed brood cappings on the board over the last 3 or 4 weeks.

Did a quick 5 min inspection yesterday to check stores & if first frame of brood was worker, all OK & sealed
Have checked board this morning & had a drop of 7 mites overnight, quite a few brood cappings, so several workers emerged overnight. Have cleaned board & will continue monitoring...

Seems unusual to have such a relatively high drop overnight & 3 weeks after the last treatment. All other colonies are strong in the same apiary, lots of stores and this one is no stronger than the others. Haven't seen any evidence of any robbing going on & weather aside from the odd day has been cool. Know drops on sticky boards are not 100% reliable, though a bit too early to be taking samples of bees to do a sugar shake, which I'll do as soon as weather warms up.

Couple of thoughts:
1. Has the 3x5 sublimation been effective? Powder was dry, hive was sealed, vapped via an eke on top of the brood box & used a Sublimox
2. Could the relatively minor disturbance from yesterday's quick inspection, have resulted in further cell cleaning, resulting in dropping already dead mites from the sublimation 3+ weeks ago? Anyone know of any evidence of delays in drops of already dead mites e.g. left in cell til cleaning dislodges?

Wondered if Forum members with experience of the '3x5day apart' sublimation treatment & monitoring afterwards, can shed any light?

Reason for concern, is last Spring I had one colony (different one) in this apiary that had a drop of 7 mites in 7 days on 7 April & by 2 May I had to start treatment resulting in a drop of 550 mites & meant a delay in adding supers in a key Spring flow period.

Thanks
 
counting mites on a drop tray is a pretty inaccurate and pointless exercise really - it proves very little apart from that there are, same as every other colony, mites present.
You would expect a pretty heavy drop during the treatment period, but afterwards................................
 
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