the TBF are now lasting a longer time. Their lifetime is increased !
1/ during the time the TBF is “extended”, there is UL blocks which are sent during this extension. They are seen as signalling. This is not a problem. You can slow the frequency of those signalling messages (t_extended_ul_poling, or something like this)
2/ the number of tbf establishments is reduced because the same TBF is reused ! So over 10 seconds, instead of using 5 TBF, the MS will use only 1 TBF. But the probability of TBF drop over those 10 seconds is the same as before 😉
Extended UL is a feature that leads to GOOD quality from subscriber point of view, but “worst” Kpi.
So, it is up to you to explain that to your management. If they want to strictly stick to KPI monitoring, without taking into account the subscriber perception, then disable this feature…