Does the forfeiture rule apply to a criminal defendant's failure to object to financial obligations imposed upon a grant of probation or sentencing?

We are well aware that as a general rule, a criminal defendant's failure to object to financial obligations imposed upon a grant of probation or sentencing constitutes forfeiture of any appellate challenges to them. (See People v. Aguilar (2015) 60 Cal.4th 862, 864 [forfeiture rule applies to challenges to probation-related costs and appointed counsel fees]; People v. Trujillo (2015) 60 Cal.4th 850, 853-854, 858 [forfeiture rule applies to challenges to probation supervision and presentence investigation fees].) Nevertheless, "[reviewing courts have traditionally excused parties for failing to raise an issue at trial where an objection would have been futile or wholly unsupported by

substantive law then in existence. [Citations.]" (People v. Welch (1993) 5 Cal.4th 228, 237-238.)

"In determining whether the significance of a change in the law excuses counsel's failure to object at trial, we consider the 'state of the law as it would have appeared to competent and knowledgeable counsel at the time of the trial.' [Citation.]" (People v. Black (2007) 41 Cal.4th 799, 811.) The forfeiture rule does not apply" 'when the pertinent law later changed so unforeseeably that it is unreasonable to expect trial counsel to have anticipated the change.' [Citations.]" (Id. at p. 810.) In applying the rule, we focus on "practical considerations as to what competent and knowledgeable members of the legal profession should reasonably have concluded the law to be." (People v. De Santiago (1969) 71 Cal.2d 18, 23.)